根据Oracle表结构生成PO实体工具类

﹏ヽ暗。殇╰゛Y 2022-04-08 09:20 511阅读 0赞

每次根据数据表写实体类和form类都觉得好麻烦，也没有装相应的工具，闲来无事就自己写了个工具类。具体代码如下：

package com.hnjz.app.common;
    
    import java.io.IOException;
    import java.io.InputStream;
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.ResultSet;
    import java.sql.ResultSetMetaData;
    import java.sql.SQLException;
    import java.sql.Statement;
    import java.util.Properties;
    
    import com.hnjz.base.db.MetaDataUtil;
    
    /**
    	 * 根据传入的数据库表名，生成po属性
    	 * 以_结尾的会去掉_ 例如：数据库字段名称 id_,实体类属性名称：id
    	 * 以_分割的，会以_分割，分割后的字符串数组从第二个字符串开始首字母大写，然后再组成最终的属性名称 
    	 * 例 :数据库字段名称unit_name，实体类属性名称：unitName
    	 * @param tableName
    	 */
    public class BuildPoByTable {
    
    	public static void buildPoByTable(String tableName){
    		Connection con = getJdbcConn();
    		Statement st = null;
    		ResultSet rs = null;
    		String sql = "select * from "+tableName;
    		try {
    			st = con.createStatement();
    			rs = st.executeQuery(sql);
    			ResultSetMetaData md = rs.getMetaData();
    			for(int i = 1;i<=md.getColumnCount();i++){
    				String columnName = md.getColumnName(i);
    				String columnType = md.getColumnTypeName(i);
    				columnName = lowerCaseChar(columnName);
                                    int xsws = md.getScale(i);//小数点右边的位数
    				//改造字段名称
    				if(columnName.endsWith("_")){
    					columnName = columnName.replace('_', ' ');
    					
    				}else if(columnName.contains("_")){
    					String[] tempName = columnName.split("_");
    					String tempstr = "";
    					for(int j=1;j<tempName.length;j++){
    						tempName[j] = PoFormConverseUtil.upCaseFirstChar(tempName[j]);
    						tempstr = tempstr+tempName[j];
    					}
    					columnName = tempName[0]+tempstr;
    				}
    				
    				if("VERSION_".equals(columnName)){
    					continue;
    				}else{
    					if("VARCHAR2".equals(columnType)||"NVARCHAR2".equals(columnType)){
    						System.out.println("private String "+columnName+";");
    					}else if("NUMBER".equals(columnType)){
    						if(xsws==0){
    							System.out.println("private Integer "+columnName+";");
    						}else if(xsws>0){
    							System.out.println("private Double "+columnName+";");
    						}
    					}else if("DATE".equals(columnType)){
    						System.out.println("private Date "+columnName+";");
    					}else if("CLOB".equals(columnType)){
    						System.out.println("private String "+columnName+";");
    					}
    				}
    
    			}
    		} catch (SQLException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}finally{
    			try {
    				con.close();
    			} catch (SQLException e) {
    				// TODO Auto-generated catch block
    				e.printStackTrace();
    			}
    		}
    		
    	}
    	
    	public static Connection getJdbcConn(){
    		Connection con = null;
            try {
            	String name = "/jdbc.properties";
                Properties p = new Properties();
                InputStream in = MetaDataUtil.class.getResourceAsStream(name);
    			p.load(in);
    			String url = p.getProperty("jdbc.url");
    	        String username = p.getProperty("jdbc.username");
    	        String password = p.getProperty("jdbc.password");
    	        String driverName = p.getProperty("jdbc.driverClassName");
    	        Class.forName(driverName);
    	        //System.out.println("加载驱动成功！");
    	        //获取数据库连接
    	        con = DriverManager.getConnection(url, username, password);
    	        //System.out.println("获取数据库连接成功！");
    	        //System.out.println("进行数据库操作！");
    	       
    		} catch (IOException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		} catch (ClassNotFoundException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		} catch (SQLException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		return con;
            
    	}
    	
    	
    	//字符串大写换小写
    	public static String lowerCaseChar(String str){
            char[] chars = str.toCharArray();
            for(int i=0;i<chars.length;i++){
            	 if (chars[i] >= 'A' && chars[i] <= 'Z') {
                     chars[i] = (char)(chars[i] + 32);
                 }
            }
           
            return new String(chars);
    	}
    	
    	
    	
    }

控制台打印如下：

private String id ;
    private String unitName;
    private String unitCode;
    private String unitAddr;
    private Double unitCapital;
    private Double unitInvestment;

字段已经有了，用myEclipse生成get，set方法即可。

注意：循环ResultSetMetaData下标从1开始，不是从0开始。

2、第二种方法（可以查出来注释）：

利用下面的sql查出指定数据库表的字段信息，生成实体类

SELECT  C.COLUMN_NAME, C.DATA_TYPE, C.DATA_SCALE, D.COMMENTS
      FROM all_tab_columns C, all_col_comments D
     WHERE C.TABLE_NAME = D.TABLE_NAME
       AND C.OWNER = D.OWNER
       AND C.TABLE_NAME = 'tabname'
       AND D.TABLE_NAME = 'tabname'
       AND C.COLUMN_NAME = D.COLUMN_NAME
       AND C.OWNER = 'dbusername';