Spring根据XML配置文件注入属性的方法
方法一使用setter方法
package com.swift;
public class Book {
 private String bookName;
 public void setBook(String bookName) {
  this.bookName = bookName;
 }
 @Override
 public String toString() {
  return "Book [book=" + bookName + "]";
 }
}
在Spring框架中,假定Servlet类中不能直接生成Book类的对象,并注入String bookName的属性值
而需要通过配置文件xml的方法
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <!-- IoC 控制反转 SpringSpring根据XML配置文件注入属性 --> <bean id="book" class="com.swift.Book"> <property name="bookName" value="三体——黑暗森林"></property> </bean> </beans>
Servlet类代码:
package com.swift;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
@WebServlet("/book")
public class BookServlet extends HttpServlet {
 private static final long serialVersionUID = 1L;
 public BookServlet() {
  super();
 }
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  response.setCharacterEncoding("utf-8");
  response.setContentType("text/html;charset=utf-8");
  response.getWriter().append("Served at: ").append(request.getContextPath());
  @SuppressWarnings("resource")
  //就是下边这几句了
  ApplicationContext context=new ClassPathXmlApplicationContext("a.xml");
  Book book=(Book) context.getBean("book");
  String bookInfo=book.fun();
  response.getWriter().println();
  response.getWriter().append(bookInfo);
 }
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doGet(request, response);
 }
}
注意
beans 、context、core 和expression核心jar包
以及commons-logging 和log4j两个jar包不要缺少
方法二使用有参构造方法
以上这篇Spring根据XML配置文件注入属性的方法就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持我们。
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