Unit06： Spring对JDBC的 整合支持 、 Spring+JDBC Template、Spring异常处理

Unit06： Spring对JDBC的 整合支持 、 Spring+JDBC Template 、Spring异常处理

1. springmvc提供的异常处理机制

我们可以将异常抛给spring框架，让spring来帮我们处理异常。

(1)使用简单异常处理器

step1. 配置简单异常处理器。

step2. 添加对应的异常处理页面。
注：该方式只适合处理简单异常的处理，如果要对异常做复杂处理，比如 记录日志等，则不合适了。

(2)使用@ExceptionHandler注解

step1. 在处理器类当中，添加一个异常处理方法， 该方法要使用@ExceptionHandler注解来标注。

 

step2.添加对应的异常处理页面。

2. SpringJdbc

(1)SpringJdbc是什么?

是spring框架中的一个模块，对jdbc api做了封装，简化了 jdbc的代码(比如，不用考虑获取连接与关闭连接了)

(2)编程步骤

step1. 导包。

step2. 添加spring配置文件。
step3. 添加JdbcTemplate配置。

注:JdbcTemplate对jdbc的api做了封装。
step4. 调用JdbcTemplate提供的方法。
注：通常将JdbcTemplate注入到DAO。

 

 

• springmvc提供的异常处理机制代码

src/main/java

controller

package controller;

import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class HelloController {
    @ExceptionHandler
    public String handler(Exception ex,
            HttpServletRequest request){
        System.out.println("handler()");
        /*
         * 依据异常类型，分别进行相应的处理。
         * ex:就是方法所抛出的异常。
         */
        if(ex instanceof NumberFormatException){
            request.setAttribute("msg",
                    "亲，请输入正确的数字");
            return "error";
        }else if(ex instanceof 
                StringIndexOutOfBoundsException){
            request.setAttribute("msg",
                    "下标越界了");
            return "error";
        }else{
            //其它异常
            return "sys_error";
        }
    }
    
    @RequestMapping("/toHello.do")
    public String toHello(){
        System.out.println("toHello()");
        String str = "123a";
        Integer.parseInt(str);
        return "hello";
    }
    
    @RequestMapping("/toHello2.do")
    public String toHello2(){
        System.out.println("toHello2()");
        String str = "abcd";
        str.charAt(10);
        return "hello";
    }
}

HelloController.java

interceptors

package interceptors;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

public class SomeInterceptor implements 
HandlerInterceptor{

    /**
     * 最后执行的方法。
     * ex:处理器所抛出的异常。
     */
    public void afterCompletion(
            HttpServletRequest request, 
            HttpServletResponse response, 
            Object arg2, Exception ex)
            throws Exception {
        System.out.println("afterCompletion()");
    }

    /**
     * 在处理器已经执行完毕，正准备将处理结果
     * (ModelAndView)返回给前端控制器之前，执行
     * postHandle方法。
     * 注：可以在该方法里面，修改处理结果。
     */
    public void postHandle(
            HttpServletRequest request, 
            HttpServletResponse response, 
            Object arg2, ModelAndView mav)
            throws Exception {
        System.out.println("postHandle()");
    }

    /**
     * 如果该方法返回值为true,表示继续向后
     * 调用（即调用后面的拦截器和处理器）；
     * 如果该方法的返回值为false,则不再向后
     * 调用，返回处理结果。
     * arg2: 处理器方法对象。
     */
    public boolean preHandle(
            HttpServletRequest request, 
            HttpServletResponse response,
            Object arg2) throws Exception {
        System.out.println("preHandle()");
        return true;
    }
    
}

SomeInterceptor.java

src/main/resources

xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context" 
    xmlns:jdbc="http://www.springframework.org/schema/jdbc"  
    xmlns:jee="http://www.springframework.org/schema/jee" 
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:aop="http://www.springframework.org/schema/aop" 
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:util="http://www.springframework.org/schema/util"
    xmlns:jpa="http://www.springframework.org/schema/data/jpa"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
        http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
        http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
        http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd">
    
    <context:component-scan 
    base-package="controller"/>
    
    <bean
     class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix" value="/WEB-INF/"/> 
    <property name="suffix" value=".jsp"/> 
    bean> 
    
    
    
    
    
    
beans>

spring-mvc.xml

WEB-INF

<%@page pageEncoding="utf-8" 
contentType="text/html; charset=utf-8" %>
<html>
    <head>head>
    <body style="font-size:30px;">
        ${msg}        
    body>
html>

error.jsp

<%@page pageEncoding="utf-8" 
contentType="text/html; charset=utf-8" %>
<html>
    <head>head>
    <body style="font-size:30px;">
        请输入正确的数字
    body>
html>

ex1.jsp

<%@page pageEncoding="utf-8" 
contentType="text/html; charset=utf-8" %>
<html>
    <head>head>
    <body style="font-size:30px;">
        下标越界
    body>
html>

ex2.jsp

<h1>Hello,SpringMVCh1>

hello.jsp

<%@page pageEncoding="utf-8" 
contentType="text/html; charset=utf-8" %>
<html>
    <head>head>
    <body style="font-size:30px;">
        系统繁忙，稍后重试
    body>
html>

sys_error.jsp

xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
  <servlet>
    <servlet-name>actionservlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
    
    <init-param>
        <param-name>contextConfigLocationparam-name>
        <param-value>classpath:spring-mvc.xmlparam-value>
    init-param>
    <load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
    <servlet-name>actionservlet-name>
    <url-pattern>*.dourl-pattern>
servlet-mapping>
  
web-app>

web.xml

 

  <dependencies>
      <dependency>
          <groupId>org.springframeworkgroupId>
          <artifactId>spring-webmvcartifactId>
          <version>3.2.8.RELEASEversion>
      dependency>
  dependencies>

pom.xml

 

• Spring对JDBC的 整合支持 、 Spring+JDBC Template

SQL语句：

CREATE table emp_fre(
id number(8) primary key,
name varchar2(50),
age number(3)
);

CREATE sequence emp_seq_fre;

oracle_create_emp.sql

src/main/java

com.tarena.netctoss.controller

package com.tarena.netctoss.controller;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import com.tarena.netctoss.dao.AdminDAO;
import com.tarena.netctoss.entity.Admin;

@Controller
public class LoginController {
    
    @Resource(name="adminDAO")
    private AdminDAO dao;
    
    @RequestMapping("/toLogin.do")
    public String toLogin(){
        System.out.println("toLogin()");
        return "login";
    }
    
    
    @RequestMapping("/login.do")
    public String login(
            HttpServletRequest request){
        System.out.println("login()");
        String adminCode = 
            request.getParameter("adminCode");
        String pwd = 
            request.getParameter("pwd");
        System.out.println("adminCode:"
            + adminCode + " pwd:" + pwd);
        //使用DAO来访问数据库
        Admin admin = null;
        try{
            admin = 
                dao.findByAdminCode(adminCode);
        }catch(Exception e){
            e.printStackTrace();
            //系统异常，需要提示用户稍后重试
            return "error";
        }
        if(admin == null){
            //帐号错误
            request.setAttribute(
                    "login_failed", "帐号错误");
            return "login";
        }else{
            if(admin.getPassword().equals(pwd)){
                //登录成功
                return "redirect:toIndex.do";
            }else{
                //密码错误
                request.setAttribute(
                        "login_failed", "密码错误");
                return "login";
            }
        }
    }
    
    @RequestMapping("/toIndex.do")
    public String toIndex(){
        return "index";
    }
    
}

LoginController.java

com.tarena.netctoss.dao

package com.tarena.netctoss.dao;

import com.tarena.netctoss.entity.Admin;

public interface AdminDAO {
    public Admin findByAdminCode(String 
            adminCode);
    
}

AdminDAO.java

package com.tarena.netctoss.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.annotation.Resource;
import javax.sql.DataSource;

import org.springframework.stereotype.Repository;

import com.tarena.netctoss.entity.Admin;

@Repository("adminDAO") 
public class AdminDAOJdbcImpl implements 
    AdminDAO{
    
    @Resource(name="ds")
    private DataSource ds;
    
    public Admin findByAdminCode(
            String adminCode) {
        Admin admin = null;
        Connection conn = null;
        try {
            conn = ds.getConnection();
            String sql = 
                "select * from admin_info_lhh "
                    + "where admin_code=?";
            PreparedStatement ps = 
                    conn.prepareStatement(sql);
            ps.setString(1, adminCode);
            ResultSet rs = 
                    ps.executeQuery();
            if(rs.next()){
                admin = new Admin();
                admin.setAdminId(rs.getInt("admin_id"));
                admin.setAdminCode(rs.getString("admin_code"));
                admin.setPassword(rs.getString("password"));
                admin.setName(rs.getString("name"));
                admin.setTelephone(rs.getString("telephone"));
                admin.setEmail(rs.getString("email"));
                admin.setEnrolldate(rs.getTimestamp("enrolldate"));
            }
        } catch (SQLException e) {
            //记日志
            e.printStackTrace();
            /*
             * 要看异常能否恢复，如果能够恢复，
             * 则立即恢复，如果不能够恢复(
             * 比如，数据库服务停止，一般称这样
             * 的异常为系统异常),则提示用户稍后
             * 重试。
             */
            throw new RuntimeException(e);
        }finally{
            if(conn != null){
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                    throw new RuntimeException(e);
                }
            }
        }
        return admin;
    }

}

AdminDAOJdbcImpl.java

com.tarena.netctoss.entity

package com.tarena.netctoss.entity;

import java.io.Serializable;
import java.sql.Timestamp;

public class Admin implements Serializable {

    private Integer adminId;
    private String adminCode;
    private String password;
    private String name;
    private String telephone;
    private String email;
    private Timestamp enrolldate;
    
    @Override
    public String toString() {
        return "Admin [adminId=" + adminId + ", adminCode=" + adminCode + ", password=" + password + ", name=" + name
                + ", telephone=" + telephone + ", email=" + email + ", enrolldate=" + enrolldate + "]";
    }
    
    public Integer getAdminId() {
        return adminId;
    }
    public void setAdminId(Integer adminId) {
        this.adminId = adminId;
    }
    public String getAdminCode() {
        return adminCode;
    }
    public void setAdminCode(String adminCode) {
        this.adminCode = adminCode;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getTelephone() {
        return telephone;
    }
    public void setTelephone(String telephone) {
        this.telephone = telephone;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public Timestamp getEnrolldate() {
        return enrolldate;
    }
    public void setEnrolldate(Timestamp enrolldate) {
        this.enrolldate = enrolldate;
    }
    
}

Admin.java

src/main/resources

# db connection parameters
# key=value
driver=oracle.jdbc.driver.OracleDriver
url=jdbc:oracle:thin:@192.168.201.227:1521:orcl
user=openlab
pwd=open123
# datasource parameters
initSize=1
maxSize=1

db.properties

xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context" 
    xmlns:jdbc="http://www.springframework.org/schema/jdbc"  
    xmlns:jee="http://www.springframework.org/schema/jee" 
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:aop="http://www.springframework.org/schema/aop" 
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:util="http://www.springframework.org/schema/util"
    xmlns:jpa="http://www.springframework.org/schema/data/jpa"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
        http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
        http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
        http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd">
    
    <context:component-scan 
    base-package="com.tarena.netctoss"/>
    
    <bean
     class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix" value="/WEB-INF/"/> 
    <property name="suffix" value=".jsp"/> 
    bean> 
    
    
    <util:properties id="db" 
    location="classpath:db.properties"/>
    
    
    <bean id="ds" 
    class="org.apache.commons.dbcp.BasicDataSource"       
       destroy-method="close">       
  <property name="driverClassName" 
  value="#{db.driver}" />      
  <property name="url" 
  value="#{db.url}" />      
  <property name="username" 
  value="#{db.user}" />      
  <property name="password" 
  value="#{db.pwd}" />      
bean> 
    
beans>

spring-mvc.xml

src/test/java

test

package test;

import java.sql.SQLException;

import javax.sql.DataSource;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.tarena.netctoss.dao.AdminDAO;
import com.tarena.netctoss.entity.Admin;

public class TestCase {
    @Test
    public void test1() throws SQLException{
        ApplicationContext ac = 
        new ClassPathXmlApplicationContext(
                "spring-mvc.xml");
        DataSource ds = 
                ac.getBean("ds",
                        DataSource.class);
        System.out.println(
                ds.getConnection());
    }
    
    @Test
    //测试 DAO
    public void test2(){
        ApplicationContext ac = 
            new ClassPathXmlApplicationContext(
                    "spring-mvc.xml");    
        AdminDAO dao = 
                ac.getBean("adminDAO",
                        AdminDAO.class);
        Admin admin = 
                dao.findByAdminCode("caocao");
        System.out.println("admin:" + admin);
        
    }
}

TestCase.java

WEB-INF

<%@page pageEncoding="utf-8" 
contentType="text/html; charset=utf-8" %>
DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <title>达内－NetCTOSStitle>
        <link type="text/css" rel="stylesheet" media="all" href="styles/global.css" />
        <link type="text/css" rel="stylesheet" media="all" href="styles/global_color.css" />
        <script language="javascript" type="text/javascript">
            var timer;
            //启动跳转的定时器
            function startTimes() {
                timer = window.setInterval(showSecondes,1000);
            }

            var i = 5;
            function showSecondes() {
                if (i > 0) {
                    i--;
                    document.getElementById("secondes").innerHTML = i;
                }
                else {
                    window.clearInterval(timer);
                    location.href = "toLogin.do";
                }
            }

            //取消跳转
            function resetTimer() {
                if (timer != null && timer != undefined) {
                    window.clearInterval(timer);
                    location.href = "toLogin.do";
                }
            }
        script> 
    head>
    <body class="error_page" onload="startTimes();">
        <h1 id="error">
            遇到错误， <span id="secondes">5span> 秒后将自动跳转，立即跳转请点击 
            <a  href="javascript:resetTimer();">返回a>
        h1>
    body>
html>

error.jsp

<%@page pageEncoding="utf-8" 
contentType="text/html; charset=utf-8" %>
DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <title>达内－NetCTOSStitle>
        <link type="text/css" rel="stylesheet" media="all" href="styles/global.css" />
        <link type="text/css" rel="stylesheet" media="all" href="styles/global_color.css" /> 
    head>
    <body class="index">
        
        <div id="index_navi">
            <ul id="menu">
                <li><a href="index.html" class="index_on">a>li>
                <li><a href="role/role_list.html" class="role_off">a>li>
                <li><a href="admin/admin_list.html" class="admin_off">a>li>
                <li><a href="fee/fee_list.html" class="fee_off">a>li>
                <li><a href="account/account_list.html" class="account_off">a>li>
                <li><a href="service/service_list.html" class="service_off">a>li>
                <li><a href="bill/bill_list.html" class="bill_off">a>li>
                <li><a href="report/report_list.html" class="report_off">a>li>
                <li><a href="user/user_info.html" class="information_off">a>li>
                <li><a href="user/user_modi_pwd.html" class="password_off">a>li>
            ul>
        div>
    body>
html>

index.jsp

<%@page pageEncoding="utf-8" 
contentType="text/html; charset=utf-8"%>
DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <title>达内－NetCTOSStitle>
        <link type="text/css" rel="stylesheet" media="all" href="styles/global.css" />
        <link type="text/css" rel="stylesheet" media="all" href="styles/global_color.css" /> 
    head>
    <body class="index">
        <div class="login_box">
                <form action="login.do" 
                    method="post">
            <table>
                <tr>
                    <td class="login_info">账号：td>
                    <td colspan="2"><input name="adminCode" type="text" class="width150" />td>
                    <td class="login_error_info"><span class="required">30长度的字母、数字和下划线span>td>
                tr>
                <tr>
                    <td class="login_info">密码：td>
                    <td colspan="2"><input name="pwd" type="password" class="width150" />td>
                    <td><span class="required">30长度的字母、数字和下划线span>td>
                tr>
                <tr>
                    <td class="login_info">验证码：td>
                    <td class="width70"><input name="" type="text" class="width70" />td>
                    <td><img src="images/valicode.jpg" alt="验证码" title="点击更换" />td>  
                    <td><span class="required">验证码错误span>td>              
                tr>            
                <tr>
                    <td>td>
                    <td class="login_button" colspan="2">
                        <a href="javascript:document.forms[0].submit();"><img src="images/login_btn.png" />a>
                    td>    
                    <td><span class="required">
                    ${login_failed}span>td>                
                tr>
            table>
            form>
        div>
    body>
html>

login.jsp

xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
  <servlet>
    <servlet-name>actionservlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
    
    <init-param>
        <param-name>contextConfigLocationparam-name>
        <param-value>classpath:spring-mvc.xmlparam-value>
    init-param>
    <load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
    <servlet-name>actionservlet-name>
    <url-pattern>*.dourl-pattern>
servlet-mapping>

<filter>
    <filter-name>encodingFilterfilter-name>
    <filter-class>
        org.springframework.web.filter.CharacterEncodingFilter
    filter-class>
    <init-param>
        <param-name>encodingparam-name>
        <param-value>UTF-8param-value>
    init-param>
filter>
<filter-mapping>
    <filter-name>encodingFilterfilter-name>
    <url-pattern>/*url-pattern>
filter-mapping>
  
web-app>

web.xml

 

  <dependencies>
      <dependency>
          <groupId>org.springframeworkgroupId>
          <artifactId>spring-webmvcartifactId>
          <version>3.2.8.RELEASEversion>
      dependency>
      <dependency>
          <groupId>com.oraclegroupId>
          <artifactId>ojdbc14artifactId>
          <version>10.2.0.4.0version>
      dependency>
      <dependency>
          <groupId>commons-dbcpgroupId>
          <artifactId>commons-dbcpartifactId>
          <version>1.4version>
      dependency>
      <dependency>
          <groupId>junitgroupId>
          <artifactId>junitartifactId>
          <version>4.12version>
      dependency>
  dependencies>

pom.xml

 

转载于:https://www.cnblogs.com/tangshengwei/p/6517409.html