Mybatis生成器插件扩展，定制方法生成，list参数生成

曾经终败给现在 2022-12-29 02:12 107阅读 0赞

Mybatis生成器插件扩展，定制方法生成

public Criteria andNameIsEmpty() {
                addCriterion("`name` = ''");
                setCriterionPattern();
                return (Criteria) this;
            }
    
            public Criteria andNameFindInSet(String value) {
                addCriterion("find_in_set($value, `name`)", value, "name");
                setCriterionPattern();
                return (Criteria) this;
            }
    
            public Criteria andNameFindInSetIn(List<String> value) {
                addCriterion("find_in_set($value, `name`)", value, "name");
                setCriterionPattern();
                return (Criteria) this;
            }

### 一、生成模式原理 ###

（1）Example.Criterion添加pattern字段

public static class Criterion {
            private String condition;
    
            private Object value;
    
            private Object secondValue;
    
            private boolean noValue;
    
            private boolean singleValue;
    
            private boolean betweenValue;
    
            private boolean listValue;
    
            private String typeHandler;
    
            private boolean pattern;
    }

（2）Example.GeneratedCriteria加方法setCriterionPattern

protected abstract static class GeneratedCriteria
    
            protected void setCriterionPattern() {
                Criterion criterion = (Criterion)criteria.get(criteria.size()-1);
                criterion.setPattern(true);
            }
    }

（3） 加对应列方法

protected abstract static class GeneratedCriteria {
    
            public Criteria andXXXOp(String value) {
                addCriterion("Op(##value##, `xxx`)", value, "xxx");
                setCriterionPattern();
                return (Criteria) this;
            }
    }

（4）改造XXXSqlProvider.applyWhere的 if (criterion.isNoValue()) 前增加模式代码

if (criterion.isPattern()) {
    	if (criterion.isListValue()) {//list参数
    		sb.append(" (");
    		List<?> listItems = (List<?>) criterion.getValue();
    		boolean comma = false;
    		for (int k = 0; k < listItems.size(); k++) {
    			if (comma) {
    				sb.append(" or ");
    			} else {
    				comma = true;
    			}
    			String value;
    			if (criterion.getTypeHandler() == null) {
    				value = String.format(parmPhrase3, i, j, k);
    			} else {
    				value = String.format(parmPhrase3_th, i, j, k, criterion.getTypeHandler());
    			}
    			sb.append(criterion.getCondition().replace("##value##", value));
    		}
    		sb.append(')');
    	} else {//其他参数
    		String value;
    		if (criterion.getTypeHandler() == null) {
    			value = String.format(parmPhrase1, "", i, j).trim();
    		} else {
    			value = String.format(parmPhrase1_th, "", i, j, criterion.getTypeHandler()).trim();
    		}
    		sb.append(criterion.getCondition().replace("##value##", value));
    	}
    } else if (criterion.isNoValue()) {
    	sb.append(criterion.getCondition());
    }

（5）改造XXXMapper.xml的<when test="criterion.noValue">前增加模式代码

<when test="criterion.pattern">
      and
      <choose>
    	<when test="criterion.listValue">
    	  <foreach close=")" collection="criterion.value" item="listItem" open="(" separator=" or  ">
    		<foreach collection="criterion.condition.split('##value##')" item="criterionCond" separator="#{listItem}">
    		  ${criterionCond}
    		</foreach>
    	  </foreach>
    	</when>
    	<otherwise>
    	  <foreach collection="criterion.condition.split('##value##')" item="criterionCond" separator="#{criterion.value}">
    		${criterionCond}
    	  </foreach>
    	</otherwise>
      </choose>
    </when>
    <when test="criterion.noValue">
      and ${criterion.condition}
    </when>

### 二、插件代码 ###

package com.mk.mybatisgenerator.plugins;
    
    import org.mybatis.generator.api.IntrospectedColumn;
    import org.mybatis.generator.api.IntrospectedTable;
    import org.mybatis.generator.api.PluginAdapter;
    import org.mybatis.generator.api.dom.java.*;
    import org.mybatis.generator.api.dom.xml.Attribute;
    import org.mybatis.generator.api.dom.xml.Element;
    import org.mybatis.generator.api.dom.xml.TextElement;
    import org.mybatis.generator.api.dom.xml.XmlElement;
    import org.mybatis.generator.codegen.ibatis2.Ibatis2FormattingUtilities;
    
    import java.util.*;
    
    public class MySQLMethodPlugin extends PluginAdapter {
    
        private String valueName = "##value##";//值占位符
        private String columnName = "##column##";//列名占位符
        private boolean listValue = true;//是否开启生成list参数
    
        private Map<String, String> methods = new HashMap<>();
    
        public MySQLMethodPlugin() {
            super();
        }
    
        @Override
        public void setProperties(Properties properties) {
            super.setProperties(properties);
    
            final String valueNameStr = "VALUE_NAME";
            final String columnNameStr = "COLUMN_NAME";
            final String listValueStr = "LIST_VALUE";
    
            for (String name : properties.stringPropertyNames()) {
                String value = properties.getProperty(name);
                if (valueNameStr.equals(name)) {
                    if (value != null && (value = value.trim()).length() > 0) {
                        this.valueName = value;
                    }
                } else if (columnNameStr.equals(name)) {
                    if (value != null && (value = value.trim()).length() > 0) {
                        this.columnName = value;
                    }
                } else if (listValueStr.equals(name)) {
                    if (value != null) {
                        this.listValue = Boolean.parseBoolean(value);
                    }
    
                } else {
                    methods.put(name, value);
                }
            }
        }
    
        @Override
        public boolean validate(List<String> warnings) {
            return true;
        }
    
    
        /**
         * 重写example
         *
         * @param topLevelClass
         * @param introspectedTable
         * @return
         */
        @Override
        public boolean modelExampleClassGenerated(TopLevelClass topLevelClass,
                                                  IntrospectedTable introspectedTable) {
    
            addCriterionPattern(topLevelClass, introspectedTable);//增加模式匹配
            if (methods.isEmpty()) {
                addFindInSet(topLevelClass, introspectedTable);//增加find_in_set方法
                addPattern(topLevelClass, introspectedTable);//增加模式方法
            } else {
                for (Map.Entry<String, String> entry : methods.entrySet()) {
                    boolean hasValue = entry.getValue().contains(valueName);
                    addMethodPattern(topLevelClass, introspectedTable, entry.getKey(), entry.getValue(), hasValue);
    
                }
            }
            return true;
        }
    
        //<when test="criterion.pattern">
        //	and
        //	<choose>
        //		<when test="criterion.listValue">
        //			<foreach close=")" collection="criterion.value" item="listItem" open="("
        //					 separator=" or  ">
        //				<foreach collection="criterion.conditionList('##value##')"
        //						 item="criterionCond" separator="#{listItem}">
        //					${criterionCond}
        //				</foreach>
        //			</foreach>
        //
        //		</when>
        //		<otherwise>
        //			<foreach collection="criterion.conditionSplit('##value##')"
        //					 item="criterionCond" separator="#{criterion.value}">
        //				${criterionCond}
        //			</foreach>
        //		</otherwise>
        //	</choose>
        //</when>
        //<when test="criterion.noValue">
        //	and ${criterion.condition}
        //</when>
    
        /**
         * xml ExampleWhere重写
         *
         * @param xmlElement
         * @param introspectedTable
         * @return
         */
        @Override
        public boolean sqlMapExampleWhereClauseElementGenerated(XmlElement xmlElement, IntrospectedTable introspectedTable) {
    
            List<Element> elementList = new LinkedList<>();
            elementList.add(xmlElement);
            while (!elementList.isEmpty()) {
                Element parent = elementList.remove(0);
                if(!(parent instanceof XmlElement)){
                    continue;
                }
                XmlElement xmlParent = (XmlElement) parent;
                List<Element> elements = xmlParent.getElements();
                elementList.addAll(0, elements);
                for (int i = 0, len = elements.size(); i < len; i++) {
                    Element ele = elements.get(i);
                    if(!(ele instanceof XmlElement)){
                        continue;
                    }
                    XmlElement element = (XmlElement) ele;
                    if(!element.getName().equals("when")){
                        continue;
                    }
                    for (Attribute attribute : element.getAttributes()) {
                        //找到criterion.noValue行插入模式代码
                        if (attribute.getName().equals("test") && attribute.getValue().equals("criterion.noValue")) {
    
                            //isList
                            XmlElement patternListWhenElement = new XmlElement("when");
                            {
    
                                XmlElement condForElement = new XmlElement("foreach");
                                condForElement.addAttribute(new Attribute("collection", "criterion.conditionSplit('" + valueName + "')"));
                                condForElement.addAttribute(new Attribute("item", "criterionCond"));
                                condForElement.addAttribute(new Attribute("separator", "#{listItem}"));
                                condForElement.addElement(new TextElement("${criterionCond}"));
    
                                XmlElement listForElement = new XmlElement("foreach");
                                listForElement.addAttribute(new Attribute("collection", "criterion.value"));
                                listForElement.addAttribute(new Attribute("item", "listItem"));
                                listForElement.addAttribute(new Attribute("separator", " or  "));
                                listForElement.addAttribute(new Attribute("open", "("));
                                listForElement.addAttribute(new Attribute("close", ")"));
                                listForElement.addElement(condForElement);
    
                                patternListWhenElement.addAttribute(new Attribute("test", "criterion.listValue"));
                                patternListWhenElement.addElement(listForElement);
                            }
                            //otherwise
                            XmlElement otherwiseElement = new XmlElement("otherwise");
                            {
                                XmlElement condForElement = new XmlElement("foreach");
                                condForElement.addAttribute(new Attribute("collection", "criterion.conditionSplit('" + valueName + "')"));
                                condForElement.addAttribute(new Attribute("item", "criterionCond"));
                                condForElement.addAttribute(new Attribute("separator", "#{criterion.value}"));
                                condForElement.addElement(new TextElement("${criterionCond}"));
                                otherwiseElement.addElement(condForElement);
                            }
    
                            XmlElement patternChooseElement = new XmlElement("choose");
                            patternChooseElement.addElement(patternListWhenElement);
                            patternChooseElement.addElement(otherwiseElement);
    
    
                            XmlElement patternElement = new XmlElement("when");
                            patternElement.addAttribute(new Attribute("test", "criterion.pattern"));
    
                            patternElement.addElement(new TextElement("and"));
                            patternElement.addElement(patternChooseElement);
                            xmlParent.addElement(i, patternElement);
                            return true;
                        }
                    }
                }
            }
    
    
            throw new RuntimeException("ChooseElement not exist");
        }
    
        //if (criterion.isPattern()) {
        //	if (criterion.isListValue()) {
        //		sb.append(" (");
        //		List<?> listItems = (List<?>) criterion.getValue();
        //		boolean comma = false;
        //		for (int k = 0; k < listItems.size(); k++) {
        //			if (comma) {
        //				sb.append(" or ");
        //			} else {
        //				comma = true;
        //			}
        //			String value;
        //			if (criterion.getTypeHandler() == null) {
        //				value = String.format(parmPhrase3, i, j, k);
        //			} else {
        //				value = String.format(parmPhrase3_th, i, j, k, criterion.getTypeHandler());
        //			}
        //			sb.append(criterion.getCondition().replace("##value##", value));
        //		}
        //		sb.append(')');
        //	} else {
        //		String value;
        //		if (criterion.getTypeHandler() == null) {
        //			value = String.format(parmPhrase1, "", i, j).trim();
        //		} else {
        //			value = String.format(parmPhrase1_th, "", i, j, criterion.getTypeHandler()).trim();
        //		}
        //		sb.append(criterion.getCondition().replace("##value##", value));
        //	}
        //} else if (criterion.isNoValue()) {
        //	sb.append(criterion.getCondition());
        //}
    
        /**
         * 重写ApplyWhere方法
         *
         * @param method
         * @param topLevelClass
         * @param introspectedTable
         * @return
         */
        @Override
        public boolean providerApplyWhereMethodGenerated(Method method, TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {
    
            List<String> lines = method.getBodyLines();
            for (int i = 0, len = lines.size(); i < len; i++) {
                String line = lines.get(i).trim();
                //找到criterion.noValue行插入模式代码
                if (line.matches("if\\s*\$criterion\\.isNoValue\\(\$\\)\\s*\\{")) {
                    lines.remove(i);
                    List<String> appends = new ArrayList<>();
                    appends.add("if (criterion.isPattern()) {");
    
                    appends.add("if (criterion.isListValue()) {");
                    appends.add("sb.append(\" (\");");
                    appends.add("List<?> listItems = (List<?>) criterion.getValue();");
                    appends.add("boolean comma = false;");
                    appends.add("for (int k = 0; k < listItems.size(); k++) {");
                    appends.add("if (comma) {");
                    appends.add("sb.append(\" or \");");
                    appends.add("} else {");
                    appends.add("comma = true;");
                    appends.add("}");
                    appends.add("String value;");
                    appends.add("if (criterion.getTypeHandler() == null) {");
                    appends.add("value = String.format(parmPhrase3, i, j, k);");
                    appends.add("} else {");
                    appends.add("value = String.format(parmPhrase3_th, i, j, k, criterion.getTypeHandler());");
                    appends.add("}");
                    appends.add("sb.append(criterion.getCondition().replace(\"" + valueName + "\", value));");
                    appends.add("}");
                    appends.add("sb.append(')');");
    
                    appends.add("} else {");
    
                    appends.add("String value;");
                    appends.add("if (criterion.getTypeHandler() == null) {");
                    appends.add("value = String.format(parmPhrase1, \"\", i, j).trim();");
                    appends.add("} else {");
                    appends.add("value = String.format(parmPhrase1_th, \"\", i, j, criterion.getTypeHandler()).trim();");
                    appends.add("}");
                    appends.add("sb.append(criterion.getCondition().replace(\"" + valueName + "\", value));");
                    appends.add("}");
    
                    appends.add("} else " + line);
                    method.addBodyLines(i, appends);
                    return true;
                }
            }
            throw new RuntimeException("criterion.isNoValue() not exist");
        }
    
        /*
            protected void setCriterionPattern() {
                Criterion criterion = (Criterion)criteria.get(criteria.size()-1);
                criterion.setPattern(true);
            }
             */
        public void addCriterionPattern(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {
    
            addCriterionPatternField(topLevelClass, introspectedTable);
    
            InnerClass criteria = null;
            // first, find the Criteria inner class
            for (InnerClass innerClass : topLevelClass.getInnerClasses()) {
                if ("GeneratedCriteria".equals(innerClass.getType().getShortName())) { //$NON-NLS-1$
                    criteria = innerClass;
                    break;
                }
            }
            if (criteria == null) {
                throw new RuntimeException("GeneratedCriteria not exist");
            }
    
            //模式方法
            Method setCriterionPattern = new Method();
            setCriterionPattern.setVisibility(JavaVisibility.PROTECTED);
            setCriterionPattern.setName("setCriterionPattern");
            setCriterionPattern.addBodyLine("Criterion criterion = (Criterion)criteria.get(criteria.size()-1);");
            setCriterionPattern.addBodyLine("criterion.setPattern(true);");
            criteria.addMethod(setCriterionPattern);
    
    
        }
    
        public void addCriterionPatternField(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {
            InnerClass criterion = null;
            // first, find the Criteria inner class
            for (InnerClass innerClass : topLevelClass.getInnerClasses()) {
                if ("Criterion".equals(innerClass.getType().getShortName())) { //$NON-NLS-1$
                    criterion = innerClass;
                    break;
                }
            }
            if (criterion == null) {
                throw new RuntimeException("Criterion not exist");
            }
    
            FullyQualifiedJavaType booleanPrimitive = FullyQualifiedJavaType.getBooleanPrimitiveInstance();
    
            Field pattern = new Field();
            pattern.setName("pattern");
            pattern.setVisibility(JavaVisibility.PRIVATE);
            pattern.setType(booleanPrimitive);
            criterion.addField(pattern);
    
            Method setPattern = new Method();
            setPattern.setVisibility(JavaVisibility.PUBLIC);
            setPattern.setName("setPattern");
            setPattern.addParameter(new Parameter(booleanPrimitive, "pattern"));
            setPattern.addBodyLine("this.pattern = pattern;");
            criterion.addMethod(setPattern);
    
            Method isPattern = new Method();
            isPattern.setVisibility(JavaVisibility.PUBLIC);
            isPattern.setReturnType(booleanPrimitive);
            isPattern.setName("isPattern");
            isPattern.addBodyLine("return pattern;");
            criterion.addMethod(isPattern);
    
            Method conditionList = new Method();
            conditionList.setVisibility(JavaVisibility.PUBLIC);
            conditionList.addParameter(new Parameter(FullyQualifiedJavaType.getStringInstance(), "valueName"));
            conditionList.setName("conditionSplit");
            conditionList.setReturnType(new FullyQualifiedJavaType("String[]"));
            conditionList.addBodyLine("return java.util.regex.Pattern.compile(valueName, java.util.regex.Pattern.LITERAL).split(this.condition);");
            criterion.addMethod(conditionList);
        }
    
        public void addFindInSet(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {
    
            String opName = "findInSet";
            String pattern = "find_in_set(" + valueName + ", " + columnName + ")";
            addMethodPattern(topLevelClass, introspectedTable, opName, pattern, true);
        }
    
    
        public void addMethodPattern(TopLevelClass topLevelClass, IntrospectedTable introspectedTable, String opName, String pattern, boolean hasValue) {
    
            addMethodPattern(topLevelClass, introspectedTable, opName, pattern, hasValue, false);
            if (hasValue && listValue) {
                addMethodPattern(topLevelClass, introspectedTable, opName, pattern, true, true);
            }
        }
    
        public void addMethodPattern(TopLevelClass topLevelClass, IntrospectedTable introspectedTable, String opName,
                                     String pattern, boolean hasValue, boolean isList) {
            InnerClass criteria = null;
            // first, find the Criteria inner class
            for (InnerClass innerClass : topLevelClass.getInnerClasses()) {
                if ("GeneratedCriteria".equals(innerClass.getType().getShortName())) { //$NON-NLS-1$
                    criteria = innerClass;
                    break;
                }
            }
    
            if (criteria == null) {
                throw new RuntimeException("GeneratedCriteria not exist");
            }
    
            for (IntrospectedColumn introspectedColumn : introspectedTable
                    .getNonBLOBColumns()) {
                if (!introspectedColumn.isJdbcCharacterColumn()
                        || !introspectedColumn.isStringColumn()) {
                    continue;
                }
    
                Method method = new Method();
                method.setVisibility(JavaVisibility.PUBLIC);
    
                //判断是否有参数
                if (hasValue) {
                    FullyQualifiedJavaType javaType = introspectedColumn.getFullyQualifiedJavaType();
                    if (isList) {//判断是否是list参数
                        javaType = FullyQualifiedJavaType.getNewListInstance();
                        javaType.addTypeArgument(introspectedColumn.getFullyQualifiedJavaType());
                    }
                    method.addParameter(new Parameter(javaType, "value")); //$NON-NLS-1$
                }
                StringBuilder opNameBuilder = new StringBuilder(opName);
                opNameBuilder.setCharAt(0, Character.toUpperCase(opNameBuilder.charAt(0)));
                opName = opNameBuilder.toString();
    
                StringBuilder sb = new StringBuilder();
                sb.append(introspectedColumn.getJavaProperty());
                sb.setCharAt(0, Character.toUpperCase(sb.charAt(0)));
                sb.insert(0, "and"); //$NON-NLS-1$
                sb.append(opName);
                //list参数加In后缀
                if (hasValue && isList) {
                    sb.append("In");
                }
                method.setName(sb.toString());
                method.setReturnType(FullyQualifiedJavaType.getCriteriaInstance());
    
                sb.setLength(0);
    
                //addCriterion方法
                sb.append("addCriterion(\"")
                        .append(pattern.replace(columnName, Ibatis2FormattingUtilities.getAliasedActualColumnName(introspectedColumn)));
                //有参数使用有参方法
                if (hasValue) {
                    sb.append("\", value, \"").append(introspectedColumn.getJavaProperty());
                }
                sb.append("\");");
    
                method.addBodyLine(sb.toString());
                method.addBodyLine("setCriterionPattern();");
                method.addBodyLine("return (Criteria) this;");
    
                criteria.addMethod(method);
            }
        }
    
        public void addPattern(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {
            addPatternMethod(topLevelClass, introspectedTable, "pattern");
        }
    
        public void addPatternMethod(TopLevelClass topLevelClass, IntrospectedTable introspectedTable, String opName) {
            InnerClass criteria = null;
            // first, find the Criteria inner class
            for (InnerClass innerClass : topLevelClass.getInnerClasses()) {
                if ("GeneratedCriteria".equals(innerClass.getType().getShortName())) { //$NON-NLS-1$
                    criteria = innerClass;
                    break;
                }
            }
    
            if (criteria == null) {
                throw new RuntimeException("GeneratedCriteria not exist");
            }
    
            for (IntrospectedColumn introspectedColumn : introspectedTable
                    .getNonBLOBColumns()) {
                if (!introspectedColumn.isJdbcCharacterColumn()
                        || !introspectedColumn.isStringColumn()) {
                    continue;
                }
    
                Method method = new Method();
                method.setVisibility(JavaVisibility.PUBLIC);
                method.addParameter(new Parameter(FullyQualifiedJavaType.getStringInstance(), "pattern"));
                method.addParameter(new Parameter(introspectedColumn
                        .getFullyQualifiedJavaType(), "value"));
    
                StringBuilder opNameBuilder = new StringBuilder(opName);
                opNameBuilder.setCharAt(0, Character.toUpperCase(opNameBuilder.charAt(0)));
                opName = opNameBuilder.toString();
    
                StringBuilder sb = new StringBuilder();
                sb.append(introspectedColumn.getJavaProperty());
                sb.setCharAt(0, Character.toUpperCase(sb.charAt(0)));
                sb.insert(0, "and"); //$NON-NLS-1$
                sb.append(opName);
                method.setName(sb.toString());
                method.setReturnType(FullyQualifiedJavaType.getCriteriaInstance());
    
                sb.setLength(0);
                sb.append("addCriterion(pattern.replace(\"")
                        .append(columnName).append("\", \"")
                        .append(Ibatis2FormattingUtilities.getAliasedActualColumnName(introspectedColumn)).append("\")")
                        .append(", value, \"")
                        .append(introspectedColumn.getJavaProperty());
                sb.append("\");");
                method.addBodyLine(sb.toString());
                method.addBodyLine("setCriterionPattern();");
                method.addBodyLine("return (Criteria) this;");
    
                criteria.addMethod(method);
            }
        }
    
    }

### 三、配置插件 ###