Struts的增删改查

1、导入相关的pom依赖（struts、自定义标签库的依赖）

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.zking</groupId>
    <artifactId>struts</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>struts Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.44</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
             <groupId>org.apache.struts</groupId>
             <artifactId>struts2-core</artifactId>
             <version>2.5.16</version>
        </dependency>
         <!-- 5.3、jstl、standard -->
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>taglibs</groupId>
            <artifactId>standard</artifactId>
            <version>1.1.2</version>
        </dependency>

        <!-- 5.4、tomcat-jsp-api -->
        <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-jsp-api</artifactId>
            <version>8.0.47</version>
        </dependency>
        
    </dependencies>
    <build>
        <finalName>struts</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.7.0</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

 2、分页的tag类导入、z.tld、完成web.xml的配置

pageTag

package com.jt.tag;

import java.io.IOException;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.BodyTagSupport;

import com.jt.util.PageBean;


public class PageTag extends BodyTagSupport {

    private static final long serialVersionUID = -553969530960334073L;

    private PageBean pageBean;

    public PageBean getPageBean() {
        return pageBean;
    }

    public void setPageBean(PageBean pageBean) {
        this.pageBean = pageBean;
    }
    @Override
    public int doStartTag() throws JspException {
        JspWriter out = pageContext.getOut();
        try {
            out.print(toHTML());
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return super.doStartTag();
    }

    private String toHTML() {
        // TODO Auto-generated method stub
        StringBuilder sb=new StringBuilder();
        //拼接下一次发送请求所要提交得隐藏得form表单
        sb.append(" <form id='pageBeanForm' action='"+pageBean.getUrl()+"' method='post'> ");
        sb.append(" <input type='hidden' name='page'> ");
        Map<String, String[]> paMap = pageBean.getPaMap();
        if(paMap!=null&&paMap.size()>0) {
            Set<Entry<String, String[]>> entrySet = paMap.entrySet();
            for (Entry<String, String[]> entry : entrySet) {
                //上一次请求可能携带页码namepage得参数，但是改参数在前面以及单独赋值
                //为什么要单独赋值？因为上一次请求时第一页得数据，下一次可能时第二页，以后这前后请求page对应得值不一样，需要单独赋值
                if(!"page".equals(entry.getKey())) {
//                    <input type='hidden' name='hobby' value='1'>
//                    <input type='hidden' name='hobby' value='2'>
                    //[1,2]
                    for(String val:entry.getValue()) {
                        sb.append(" <input type='hidden' name='"+entry.getKey()+"' value='"+val+"'> ");
                    }
                }
            }
        }

        sb.append(" </form>");
        //拼接分页条
        sb.append(" <div style='text-align: right; font-size: 12px;'> ");
        sb.append(" 每页"+pageBean.getRows()+"条，共"+pageBean.getTotal()+"条，第"+pageBean.getPage()+"页，共"+pageBean.getMaxPage()+"页&nbsp;&nbsp;<a ");
        sb.append(" href='javascript:gotoPage(1)'>首页</a>&nbsp;&nbsp;<a");
        sb.append(" href='javascript:gotoPage("+pageBean.getpreviousPage()+")'>上一页</a>&nbsp;&nbsp;<a");
        sb.append(" href='javascript:gotoPage("+pageBean.getNextPage()+")'>下一页</a>&nbsp;&nbsp;<a");
        sb.append(" href='javascript:gotoPage("+pageBean.getMaxPage()+")'>尾页</a>&nbsp;&nbsp;<input type='text'");
        sb.append(" id='skipPage'");
        sb.append(" style='text-align: center; font-size: 12px;  50px;'>&nbsp;&nbsp;<a");
        sb.append(" href='javascript:skipPage()'>Go</a>");
        sb.append(" </div>");
        //拼接分页所需要得js代码
        sb.append(" <script type='text/javascript'>    ");
        sb.append(" function gotoPage(page) {");
        sb.append(" document.getElementById('pageBeanForm').page.value = page;");
        sb.append(" document.getElementById('pageBeanForm').submit();");
        sb.append(" }");
        sb.append(" function skipPage() {");
        sb.append(" var page = document.getElementById('skipPage').value;");
        sb.append(" if(!page || isNaN(page) || parseInt(page)<1 || parseInt(page)>"+pageBean.getMaxPage()+"){");
        sb.append(" alert('请输入1~N的数字');");
        sb.append(" return;");
        sb.append(" }");
        sb.append(" gotoPage(page);");
        sb.append(" }");
        sb.append(" </script>");
    
        
        return sb.toString();
    }
}

z.tld

  <tag>
    <!-- 标签库中的标签（类似c:set c:out的定义） -->
    <name>page</name>
    <!-- 是标签运行具体代码，也是助手类，下面填写的是助手类的全路径名 -->
    <tag-class>com.jt.tag.PageTag</tag-class>
    <body-content>JSP</body-content>
    <attribute>
    <!-- 该标签的属性 -->
        <name>pageBean</name>
        <!-- 该属性是否必填 -->
        <required>true</required>
        <!-- 是否支持表达式 -->
        <rtexprvalue>true</rtexprvalue>
    </attribute>
  </tag>

web.xml

<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">
  <display-name>Archetype Created Web Application</display-name>
  <filter>
      <filter-name>encodingFiter</filter-name>
      <filter-class>com.jt.util.EncodingFiter</filter-class>
  </filter>
  <filter-mapping>
       <filter-name>encodingFiter</filter-name>
       <url-pattern>/*</url-pattern>
  </filter-mapping>
  <filter>
  <filter-name>struts2</filter-name>
   <filter-class>org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>struts2</filter-name>
    <url-pattern>*.action</url-pattern>
  </filter-mapping>
</web-app>

3、dao层去访问数据

实体类

Clazz

package com.jt.entity;

public class Clazz {

    private int cid;
    private String cname;
    private String cteacher;
    private String pic="图片暂定";
    public int getCid() {
        return cid;
    }
    public void setCid(int cid) {
        this.cid = cid;
    }
    public String getCname() {
        return cname;
    }
    public void setCname(String cname) {
        this.cname = cname;
    }
    public String getCteacher() {
        return cteacher;
    }
    public void setCteacher(String cteacher) {
        this.cteacher = cteacher;
    }
    public String getPic() {
        return pic;
    }
    public void setPic(String pic) {
        this.pic = pic;
    }
    @Override
    public String toString() {
        return "Clazz [cid=" + cid + ", cname=" + cname + ", cteacher=" + cteacher + ", pic=" + pic + "]";
    }
    
}

Clazzdao

package com.jt.dao;

import java.sql.SQLException;
import java.util.List;

import org.apache.commons.lang3.StringUtils;

import com.jt.entity.Clazz;
import com.jt.util.BaseDao;
import com.jt.util.PageBean;

public class ClazzDao extends BaseDao<Clazz> {

    public List<Clazz> list(Clazz clazz,PageBean pageBean) throws InstantiationException, IllegalAccessException, SQLException{
        String sql="select * from t_struts_class where true ";
        String cname=clazz.getCname();
        int cid=clazz.getCid();
        if(cid!=0) {
            sql+="and cid ="+cid;
        }
        if(StringUtils.isNoneBlank(cname)) {
            sql+=" and cname like '%"+cname+"%'";
        }
        return super.executeQuery(sql,Clazz.class, pageBean);
    }
    public int add(Clazz clazz) throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException, SQLException {
        String sql="insert into t_struts_class values(?,?,?,?)";
        return super.executeupdate(sql, new String[] {"cid","cname","cteacher","pic"}, clazz);
    }
    public int del(Clazz clazz) throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException, SQLException {
        String sql="delete from t_struts_class where cid=?";
        return super.executeupdate(sql, new String[] {"cid"}, clazz);
    }
    public int edit(Clazz clazz) throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException, SQLException {
        String sql="update t_struts_class set cname=?,cteacher=?,pic=?";
        return super.executeupdate(sql, new String[] {"cname","cteacher","pic","cid"}, clazz);
    }
}

4、web层去调用dao层给前台返回数据

ClazzAction.java

package com.jt.web;

import java.sql.SQLException;
import java.util.List;

import com.jt.dao.ClazzDao;
import com.jt.entity.Clazz;
import com.jt.util.BaseAction;
import com.jt.util.PageBean;
import com.opensymphony.xwork2.ModelDriven;

public class ClazzAction extends BaseAction implements ModelDriven<Clazz>{

    private Clazz clz=new Clazz();
    private ClazzDao clzDao=new ClazzDao();
    public String list(){
        PageBean pageBean =new PageBean();
        pageBean.setRequest(request);
        try {
            List<Clazz> list = this.clzDao.list(clz, pageBean);
            request.setAttribute("clzList",list);
            request.setAttribute("pageBean",pageBean);
        } catch (InstantiationException | IllegalAccessException | SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return "list";
        
    }
    /**
     * 跳转编辑页面 （新增修改页面）
     * @return
     */
    public String preSave() {
        if(clz.getCid()!=0) {
            try {
                this.result= this.clzDao.list(clz, null).get(0);
                
            } catch (InstantiationException | IllegalAccessException | SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return "preSave";
        
    }
    public String add() {
        try {
            this.code= this.clzDao.add(clz);
        } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException
                | SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return "toList";
        
    }
    public String edit() {
        try {
            this.clzDao.edit(clz);
        } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException
                | SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return "toList";
        
    }
    public String del() {
        try {
            this.clzDao.del(clz);
        } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException
                | SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return "toList";
        
    }

    @Override
    public Clazz getModel() {
        // TODO Auto-generated method stub
        return clz;
    }
}

5、在struts_sy.xml进行配置

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
    "http://struts.apache.org/dtds/struts-2.5.dtd">
<struts>
    <package name="sy" extends="base" >
    
    <action name="/hello_*" class="com.jt.HelloAction" method="{1}">
      <result name="success">/success.jsp</result>
    </action>
    <action name="/clz_*" class="com.jt.web.ClazzAction" method="{1}">
      <result name="list">/clzList.jsp</result>
      <result name="preSave">/clzEdit.jsp</result>
      <result name="toList" type="redirectAction">/clz_list</result>
    </action>
    </package>
</struts>

6、写jsp

clzList.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@taglib prefix="z" uri="/jt"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
    <h2>小说目录</h2>
    <br>

    <form action="${pageContext.request.contextPath}/sy/clz_list.action"
        method="post">
        书名：<input type="text" name="bname"> <input type="submit"
            value="确定">
    </form>
    <a href="${pageContext.request.contextPath}/sy/clz_preSave.action">增加</a>
    <table border="1" width="100%">
        <tr>
            <td>编号</td>
            <td>班级名称</td>
            <td>老师</td>
            <td>班级图片</td>
        </tr>
        <c:forEach items="${clzList }" var="b">
            <tr>
                <td>${b.cid }</td>
                <td>${b.cname }</td>
                <td>${b.cteacher }</td>
                <td>${b.pic }</td>
                <td><a
                    href="${pageContext.request.contextPath}/sy/clz_preSave.action?cid=${b.cid}">修改</a>&nbsp;&nbsp;
                    <a
                    href="${pageContext.request.contextPath}/sy/clz_del.action?cid=${b.cid}">删除</a>&nbsp;
                    <a
                    href="${pageContext.request.contextPath}/sy/clz_preUpload.action?cid=${b.cid}">图片上传</a>&nbsp;
                </td>
            </tr>
        </c:forEach>
    </table>
    <z:page pageBean="${pageBean }"></z:page>
</body>
</html>

clzEdit.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="${pageContext.request.contextPath}${result.cname == null ? '/sy/clz_add.action' : '/sy/clz_edit.action'}" method="post">
   cid:<input type="text" value="${result.cid }" name="cid"><br>
   cname:<input type="text" value="${result.cname }" name="cname"><br>
  cteacher:<input type="text" value="${result.cteacher }" name="cteacher"><br>
   <input type="submit" value="ok">
</form>
</body>
</html>