Struts2之Crud综合实例

傷城~ 2022-08-21 11:56 176阅读 0赞

### 本文是Struts2的综合实例，主要包含以下功能 ###

1.  添加，删除，修改，查询用户
2.  上传，下载图片
3.  拦截器实现登陆功能
4.  验证器检查输入

### 下载图片功能以前没有实现过，步骤如下 ###

*  在类中增加两个属性

//文件下载
        private InputStream inputStream;
        private String imageFileName;

*  下载方法实现

public String download(){
            path = ServletActionContext.getRequest().getParameter("path");
            filename = ServletActionContext.getRequest().getParameter("filename");
    
            String storePath = ServletActionContext.getServletContext().getRealPath("/files");
    
            try {
                inputStream = new FileInputStream(storePath+"\\"+path+"\\"+filename);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
    
            return SUCCESS;
        }

### 配置struts.xml ###

<action name="download" class="cn.itcast.domain.User" method="download">
                <interceptor-ref name="mydefaultstack"></interceptor-ref>
                <result type="stream" name="success">
                    <param name="contentType">application/octet-stream</param>
                    <param name="inputStream">inputStream</param>
                    <param name="contentDisposition">attachment;filename=${filename}</param>
                </result>
                <result name="login">/login.jsp</result>
            </action>

### JSP页面实现 ###

<c:url value="/user/download" var="url">
                <c:param name="path" value="${user.path}"></c:param>
                <c:param name="filename" value="${user.filename}"></c:param>
            </c:url>
            <a href="${url}">下载</a>

### 登陆验证功能 ###

### 定义拦截器类 ###

package cn.itcast.interceptor;
    
    import javax.servlet.http.HttpSession;
    
    import org.apache.struts2.ServletActionContext;
    
    import com.opensymphony.xwork2.ActionInvocation;
    import com.opensymphony.xwork2.interceptor.Interceptor;
    
    public class PermissionInterceptor implements Interceptor {
        
    
        public void destroy() {
    
        }
    
        public void init() {
    
        }
    
        public String intercept(ActionInvocation invocation) throws Exception {
            HttpSession session = ServletActionContext.getRequest().getSession();
            Object obj = session.getAttribute("user");
            if(obj==null){
                return "login";
            }else{
                return invocation.invoke();
            }
        }
    
    }

### struts.xml中的配置 ###

### 在其他Action中使用拦截 ###

<interceptor-ref name="mydefaultstack"></interceptor-ref>

### 条件查询实现 ###

### JSP页面 ###

### javabean方法实现 ###

public String queryCondition(){
            List<User> users =s.findUserByCondition(this);
            ActionContext.getContext().put("users", users);// #users
            return SUCCESS;
        }

### service层方法实现 ###

public List<User> findUserByCondition(User user) {
            boolean ok1 = true;
            boolean ok2 = true;
            boolean ok3 = true;
            StringBuffer sb = new StringBuffer("where 1=1 ");
    
    
            if(user.getUsername()!=null&&!user.getUsername().equals("")){
                ok1 = false;
                sb.append(" and username like '%"+user.getUsername()+"%' ");
            }
            if(user.getSex()!=null&&!user.getSex().equals("")){
                ok2 = false;
                sb.append(" and sex='"+user.getSex()+"'");
            }
    
            if(user.getEducation()!=null&&!user.getEducation().equals("")){
                ok3 = false;
                sb.append(" and education='"+user.getEducation()+"'");
            }
    
            boolean conditionOk = ok1&&ok2&&ok3;//如果为false，说明至少有一个查询条件
            if(conditionOk){
    //          System.out.println("没有查询条件");
    //          return null;
                return dao.findUsersByCondition(null);
            }else{
    //          System.out.println("有查询条件");
    //          System.out.println(sb.toString());
    //          return null;
                return dao.findUsersByCondition(sb.toString());
            }
        }

### 其他增删改查详细实例参见github源码 ###

[ssh/Struts2Crud at master · whuhan2013/ssh][ssh_Struts2Crud at master _ whuhan2013_ssh]

### 效果如下 ###

![这里写图片描述][20160429192055660]

[ssh_Struts2Crud at master _ whuhan2013_ssh]: https://github.com/whuhan2013/ssh/tree/master/Struts2Crud
[20160429192055660]: /images/20220724/45fcb01122d244a7b0f603480045808a.png