利用struts完成增删改查

思路：

    1、导入相关的pom依赖（struts、自定义标签库的依赖)
    2、分页的tag类导入、z.tld、完成web.xml的配置
    3、dao层去访问数据
    4、web层去调用dao层给前台返回数据
    5、在struts_sy.xml进行配置
    6、写jsp

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>liyi_struts2</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>liyi_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>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>2.5.13</version>
 </dependency>
  <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>
  <dependency>
   <groupId>org.apache.tomcat</groupId>
   <artifactId>tomcat-jsp-api</artifactId>
   <version>8.0.47</version>
  </dependency>
  <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
  <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.6</version>
  </dependency>
  </dependencies>
  <build>
    <finalName>liyi_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>

分页的tag类导入、z.tld、完成web.xml的配置:
    PageTag.java

package com.liyi.crud.tag;
import java.io.IOException;
import java.util.Map;
import java.util.Map.Entry;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.BodyTagSupport;
import com.liyi.crud.util.PageBean;
public class PageTag extends BodyTagSupport {
 private static final long serialVersionUID = 2411829139570358249L;
 private PageBean pageBean;
 @Override
 public int doStartTag() throws JspException {
  JspWriter out = pageContext.getOut();
  try {
   out.write(toHTML());
  } catch (IOException e) {
   e.printStackTrace();
  }
  return super.doStartTag();
 }
 public String toHTML() {
  StringBuffer sb = new StringBuffer();
  // 下一次请求提交到后台的表单html代码拼接
  sb.append("<form id='pageBeanForm' action='" + pageBean.getUrl() + "' method='post'>");
  Map<String, String[]> paramMap = pageBean.getParameterMap();
  if (paramMap != null && paramMap.size() > 0) {
   for (Entry<String, String[]> entry : paramMap.entrySet()) {
    if (!"page".equals(entry.getKey())) {
     for(String val : entry.getValue()) {
      sb.append("<input type='hidden' name='" + entry.getKey() + "' value='" + val + "' >");
     }
    }
   }
  }
  sb.append("<input type='hidden' name='page'>");
  sb.append("</form>");
  // 分页条html代码拼接
  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; width: 50px;'>&nbsp;&nbsp;<a");
  sb.append(" href='javascript:skipPage()'>Go</a>");
  sb.append("</div>");
  // 分页所需要调用的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();
 }
 public PageBean getPageBean() {
  return pageBean;
 }
 public void setPageBean(PageBean pageBean) {
  this.pageBean = pageBean;
 }
}

    web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" 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.liyi.crud.util.EncodingFiter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>encodingFiter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
  <filter>
    <filter-name>struts</filter-name>
    <filter-class>org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>struts</filter-name>
    <url-pattern>*.action</url-pattern>
  </filter-mapping>
</web-app>

    z.tld

<?xml version="1.0" encoding="UTF-8" ?>
<taglib xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
    version="2.0">
  <description>z 1.1 core library</description>
  <display-name>z core</display-name>
  <tlib-version>1.1</tlib-version>
  <short-name>c</short-name>
  <uri>/z</uri>
  <tag>
   <!-- 标签库中的标签名 -->
    <name>page</name>
    <!-- 标签对应的助手类的全路径名 -->
    <tag-class>com.liyi.crud.tag.PageTag</tag-class>
    <!-- JSP -->
    <body-content>JSP</body-content>
    <attribute>
     <!-- 属性名 -->
        <name>pageBean</name>
        <!-- 属性值是否必填 -->
        <required>true</required>
        <!-- 是否支持表达式 -->
        <rtexprvalue>true</rtexprvalue>
    </attribute>
  </tag>
</taglib>

dao层去访问数据
    ClazzDao

package com.liyi.crud.dao;
import java.sql.SQLException;
import java.util.List;
import com.liyi.crud.entity.Clazz;
import com.liyi.crud.util.BaseDao;
import com.liyi.crud.util.PageBean;
import com.liyi.crud.util.StringUtils;
public class ClazzDao extends BaseDao<Clazz>{
 /**
  * 查询所有，查询单条数据的方法
  * @param clz
  * @param pageBean
  * @return
  * @throws InstantiationException
  * @throws IllegalAccessException
  * @throws IllegalArgumentException
  * @throws Exception
  */
 public List<Clazz> list(Clazz clz,PageBean pageBean) throws InstantiationException, IllegalAccessException, IllegalArgumentException, Exception{
  String sql = "select * from t_struts_class where true";
  String cname = clz.getCname();
  int cid = clz.getCid();
  if(cid!=0) {
   sql += " and cid="+cid;
  }
  if(StringUtils.isNotBlank(cname)) {
   sql += " and cname like '%"+cname+"%'";
  }
  return super.executeQuery(sql, Clazz.class, pageBean);
 }
 /**
  * 新增
  * @param clz
  * @return
  * @throws NoSuchFieldException
  * @throws SecurityException
  * @throws IllegalArgumentException
  * @throws IllegalAccessException
  * @throws SQLException
  * @throws InstantiationException 
  */
 public int add(Clazz clz) throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException, SQLException, InstantiationException {
  String sql = "insert into t_struts_class values(?,?,?,?)";
  return super.executeUpdate(sql, new String[] {"cid","cname","cteacher","pic"},clz);
 }
 /**
  * 修改
  * @param clz
  * @return
  * @throws NoSuchFieldException
  * @throws SecurityException
  * @throws IllegalArgumentException
  * @throws IllegalAccessException
  * @throws SQLException
  * @throws InstantiationException 
  */
 public int edit(Clazz clz) throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException, SQLException, InstantiationException {
  String sql = "update t_struts_class set cname=?,cteacher=?,pic=? where cid=?";
  return super.executeUpdate(sql, new String[] {"cname","cteacher","pic","cid"},clz);
 }
 /**
  * 删除
  * @param clz
  * @return
  * @throws NoSuchFieldException
  * @throws SecurityException
  * @throws IllegalArgumentException
  * @throws IllegalAccessException
  * @throws SQLException
  * @throws InstantiationException 
  */
 public int del(Clazz clz) throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException, SQLException, InstantiationException {
  String sql = "delete from t_struts_class where cid=?";
  return super.executeUpdate(sql, new String[] {"cid"},clz);
 }
}

Clazz

package com.liyi.crud.entity;
public class Clazz {
 private int cid;
 private String cname;
 private String cteacher;
 private String pic;
 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 + "]";
 }
 public Clazz() {
  super();
  // TODO Auto-generated constructor stub
 }
 public Clazz(int cid, String cname, String cteacher, String pic) {
  super();
  this.cid = cid;
  this.cname = cname;
  this.cteacher = cteacher;
  this.pic = pic;
 }
 public Clazz(String cname, String cteacher, String pic) {
  this.cname = cname;
  this.cteacher = cteacher;
  this.pic = pic;
 }
}

辅助类：（前面博客有的）

web层去调用dao层给前台返回数据
ClazzAction

package com.liyi.crud.web;
import java.sql.SQLException;
import java.util.List;
import com.liyi.crud.dao.ClazzDao;
import com.liyi.crud.entity.Clazz;
import com.liyi.crud.util.PageBean;
import com.opensymphony.xwork2.ModelDriven;
public class ClazzAction extends BaseAction implements ModelDriven<Clazz>{
 private ClazzDao clazzDao = new ClazzDao();
 private Clazz clz = new Clazz();
 public String list() {
  PageBean pageBean = new PageBean();
  pageBean.setRequest(request);
  try {
   List<Clazz> list = this.clazzDao.list(clz, pageBean);
   request.setAttribute("clzList", list);
   request.setAttribute("pageBean", pageBean);
  } catch (Exception e) {
   e.printStackTrace();
  }
  return "list";
 }
 /**
  * 跳转新增、修改页面的公用方法
  * @return
  */
 public String preSave() {
  if(clz.getCid()!=0) {
   Clazz c;
   try {
    c = this.clazzDao.list(clz, null).get(0);
    request.setAttribute("clz", c);
   } catch (Exception e) {
    e.printStackTrace();
   }
  }
  return "preSave";
 }
 /**
  * 新增
  * @return
  */
 public String add() {
  try {
   result = this.clazzDao.add(clz);
  } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException
    | InstantiationException | SQLException e) {
   e.printStackTrace();
  }
  return "toList";
 }
 /**
  * 修改
  * @return
  */
 public String edit() {
  try {
   this.clazzDao.edit(clz);
  } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException
    | InstantiationException | SQLException e) {
   e.printStackTrace();
  }
  return "toList";
 }
 /**
  * 刪除
  * @return
  */
 public String del() {
  try {
   this.clazzDao.del(clz);
  } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException
    | InstantiationException | SQLException e) {
   e.printStackTrace();
  }
  return "toList";
 }
 @Override
 public Clazz getModel() {
  // TODO Auto-generated method stub
  return clz;
 }
}

BaseAction

package com.liyi.crud.web;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.interceptor.ServletResponseAware;
/**
 * 每一个开发的子控制器要用的属性都定义在通用的action中。
 * @author Administrator
 *
 */
public class BaseAction implements ServletRequestAware, ServletResponseAware{
 /**
  * 为了传值使用
  */
 protected HttpServletResponse response;
 protected HttpServletRequest request;
 protected HttpSession session;
 protected ServletContext application;
 /**
  * 为了配置跳转页面所用
  */
 protected final static String SUCCESS = "success";
 protected final static String FAIL = "fail";
 protected final static String LIST = "list";
 protected final static String ADD = "add";
 protected final static String EDIT = "edit";
 protected final static String DETAIL = "detail";
 /**
  * 具体传值字段 后端向jsp页面传值所用字段
  */
 protected Object result;
 protected Object msg;
 protected int code;
 public Object getResult() {
  return result;
 }
 public Object getMsg() {
  return msg;
 }
 public int getCode() {
  return code;
 }
 @Override
 public void setServletResponse(HttpServletResponse arg0) {
  this.response = arg0;
 }
 @Override
 public void setServletRequest(HttpServletRequest arg0) {
  this.request = arg0;
  this.session = arg0.getSession();
  this.application = arg0.getServletContext();
 }
}

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" namespace="/sy">
  <action name="/demo_*" class="com.liyi.web.HelloAction" method="{1}">
   <result name="rs">/rs.jsp</result>
  </action>
  <action name="/stack_*" class="com.liyi.test.DemoAction" method="{1}">
   <result name="rs">/rs.jsp</result>
  </action>
  <action name="/clz_*" class="com.liyi.crud.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>

写jsp
clzList.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
    <%@ taglib uri="/z"  prefix="z" %>
<!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></h2>
 <br>
 <form action="${pageContext.request.contextPath}/sy/clz_list.action"
  method="post">
  班级名：<input type="text" name="cname"> <input type="submit"
   value="确定">
 </form>
 <a href="${pageContext.request.contextPath}/sy/clz_preSave.action">增加</a>
 <table border="1" width="100%">
  <tr>
   <td>编号</td>
   <td>班级名</td>
   <td>教员</td>
   <td>图片</td>
   <td>操作</td>
  </tr>
  <c:forEach items="${clzList }" var="c">
   <tr>
    <td>${c.cid }</td>
    <td>${c.cname }</td>
    <td>${c.cteacher }</td>
    <td>${c.pic }</td>
    <td>
     <a href="${pageContext.request.contextPath}/sy/clz_preSave.action?cid=${c.cid}">修改</a>
     &nbsp;
     <a href="${pageContext.request.contextPath}/sy/clz_del.action?cid=${c.cid}">删除</a>
     &nbsp;<a href="${pageContext.request.contextPath}/sy/clz_preSave.action?cid=${c.cid}">上传</a>
    </td>
   </tr>
  </c:forEach>
 </table>
 <z:page pageBean="${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="${pageContext.request.contextPath}${clz.cname==null ? '/sy/clz_add.action' : '/sy/clz_edit.action'}" method="post">
  cid:<input name="cid" value="${clz.cid }"><br>
  cname:<input name="cname" value="${clz.cname }"><br>
  cteacher:<input name="cteacher" value="${clz.cteacher }"><br>
  <input type="submit">
 </form>
</body>
</html>

实现的效果：