dwr全稱Direct Web Remoting原理將java代碼轉化成js對象，實現跨域訪問
web.xml
<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5"> <display-name>DWR (Direct Web Remoting)</display-name> <description>A Simple Demo DWR</description> <listener> <listener-class>org.directwebremoting.servlet.DwrListener</listener-class> </listener> <servlet> <servlet-name>dwr-invoker</servlet-name> <servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class> <init-param> <param-name>debug</param-name> <param-value>true</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dwr-invoker</servlet-name> <url-pattern>/dwr/*</url-pattern> </servlet-mapping> </web-app>
dwr.xml
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 3.0//EN" "http://getahead.org/dwr/dwr30.dtd"> <dwr> <allow> <!-- <filter class="com.example.dwr.monitor.MonitoringAjaxFilter"/> <filter class="org.directwebremoting.filter.ExtraLatencyAjaxFilter"> <param name="delay" value="200"/> </filter> --> <!-- intro - for the test on index.html --> <create creator="new"> <param name="class" value="org.konghao.dwr.model.MyDwr"/> </create> <convert converter="bean" match="org.konghao.dwr.model.User"/> <convert converter="bean" match="org.konghao.dwr.model.Group"/> <convert match="java.lang.Exception" converter="exception"/> <convert converter="bean" match="java.lang.StackTraceElement"/> </allow> </dwr>
package org.konghao.dwr.model;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.FilenameUtils;
import org.directwebremoting.WebContext;
import org.directwebremoting.WebContextFactory;
public class MyDwr {
public String hello(String world) {
System.out.println("hello "+world);
return "hello "+world;
}
public User load() {
User u = new User(1,"張三",new Group(1,"財務處"));
return u;
}
public List<User> list() {
List<User> users = new ArrayList<User>();
users.add(new User(1,"張三",new Group(1,"財務處")));
users.add(new User(2,"李四",new Group(2,"科技處")));
users.add(new User(3,"王五",new Group(3,"宣傳部")));
return users;
}
public void add(User user) {
System.out.println(user);
}
public void deleteUser() {
throw new MyException("在刪除用戶的時候有錯");
}
public int add(int a,int b) {
return a+b;
}
public String upload(InputStream is,String filename) throws IOException {
//WebContext可以獲取HttpServlet的對象
WebContext wc = WebContextFactory.get();
HttpServletRequest req = wc.getHttpServletRequest();
String realpath = req.getSession().getServletContext().getRealPath("upload");
String fn = FilenameUtils.getName(filename);
String filepath = realpath+"/"+fn;
FileUtils.copyInputStreamToFile(is, new File(filepath));
return filepath;
}
}package org.konghao.dwr.model;
public class MyException extends RuntimeException {
public MyException() {
super();
// TODO Auto-generated constructor stub
}
public MyException(String message, Throwable cause) {
super(message, cause);
// TODO Auto-generated constructor stub
}
public MyException(String message) {
super(message);
// TODO Auto-generated constructor stub
}
public MyException(Throwable cause) {
super(cause);
// TODO Auto-generated constructor stub
}
}package org.konghao.dwr.model;
public class User {
private int id;
private String username;
private Group group;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public Group getGroup() {
return group;
}
public void setGroup(Group group) {
this.group = group;
}
public User(int id, String username, Group group) {
super();
this.id = id;
this.username = username;
this.group = group;
}
public User() {
super();
}
@Override
public String toString() {
return "User [id=" + id + ", username=" + username + ", group=" + group
+ "]";
}
}package org.konghao.dwr.model;
public class Group {
private int id;
private String name;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Group(int id, String name) {
super();
this.id = id;
this.name = name;
}
public Group() {
super();
}
@Override
public String toString() {
return "Group [id=" + id + ", name=" + name + "]";
}
}無刷新上傳文件
<%@ 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>
<script type="text/javascript" src="<%=request.getContextPath()%>/dwr/engine.js"></script>
<script type="text/javascript" src="<%=request.getContextPath()%>/dwr/util.js"></script>
<script type="text/javascript" src="<%=request.getContextPath()%>/dwr/interface/MyDwr.js"></script>
<script type="text/javascript">
function upload() {
var file = dwr.util.getValue("myfile");
alert(file.value);
alert(file);
MyDwr.upload(file,file.value,function(data){
alert(data);
});
}
</script>
</head>
<body>
<input type="file" id="myfile"/>
<input type="button" value="上傳文件" onclick="upload()"/>
</body>
</html>