Be careful:
Project: war and project: war expanded
They are not the same. idea runs the project: war expanded
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.3.10.RELEASE</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.3.3</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.7</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.9.7</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>2.9.7</version>
</dependency>Required dependencies:
Commons file upload: file upload
jackson.core: three jackson packages
web.xml, Springmvc.xml, as configured in the previous issue
package com.hc.controller;
import com.hc.entity.Point;
import com.hc.entity.Student;
import org.apache.commons.io.FileUtils;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@Controller
public class FirstController {
@RequestMapping("load")
public String load(MultipartFile file,HttpServletRequest request){
// System.out.println("name \ t"+file.getOriginalFilename());
// System.out.println("size \ t"+file.getSize());
// System.out.println("name\t"+file.getName());
//
// System.out.println("file path \ t"+request.getRealPath("/images"));
//+System.currentTimeMillis()
String path=request.getRealPath("/images");
File f=new File(path+"/"+file.getOriginalFilename());
try {
FileUtils.copyInputStreamToFile(file.getInputStream(),f);
} catch (IOException e) {
e.printStackTrace();
}
return "success";
}
@RequestMapping("point")
public String point(Point point){
System.out.println(point);
return "success";
}
@RequestMapping("first")
public String first(HttpServletRequest request){
request.setAttribute("id",12);
return "forward:forWard.action";
}
@RequestMapping("forWard")
public String forWard(HttpServletRequest request){
System.out.println("forWard\t"+request.getAttribute("id"));
return "success";
}
@ResponseBody
@RequestMapping("json")
public Map<String,Object> json(){
Map<String,Object> map=new HashMap<>();
List<Student> studentList=new ArrayList<>();
studentList.add(new Student("word","female",12));
studentList.add(new Student("still","male",32));
map.put("size",studentList.size());
map.put("students",studentList);
return map;
}
}
1.forward: can forward data
Forwarding: data can be forwarded to the page without change of address
Redirect: skip to another page without transferring data, and the address will change to the target page.
2.ResponseBody: automatic conversion
More convenient than fastjson
Data in json format
{"size":2,"students":[{"stuId":0,"stuName":"word","stuSex":"female","stuAge":12},{"stuId":0,"stuName":"still","stuSex":"male","stuAge":32}]}
3. Collect date data of util
user:
import java.util.Date;
public class Users {
private String uname;
private String upwd;
@DateTimeFormat(pattern = "yyyy-MM-dd")
private Date birthday;
}Turn on the DateTimeFormat annotation on the attributes that need special collection for entity classes
<mvc:annotation-driven></mvc:annotation-driven>
Configuring annotation driver in spring MVC
4. Collect coordinates
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<form action="/load.action" method="post" enctype="multipart/form-data">
<input type="file" name="file">
<input type="submit" value="load">
</form>
first
<a href="/first.action">success</a>
<form action="/point.action" method="post">
<input type="text" name="point">
<input type="submit" value="ok">
</form>
</body>
</html>
Coordinate format: (2, 3)
First, customize the converter
package com.hc.controller;
import com.hc.entity.Point;
import org.springframework.core.convert.converter.Converter;
public class PointConverter implements Converter<String,Point> {
@Override
public Point convert(String s) {
String[] strings=s.split("-");
int x=Integer.parseInt(strings[0]);
int y=Integer.parseInt(strings[1]);
Point point=new Point(x,y);
return point;
}
}
Build a point object with properties x and y
Configure a custom converter
<bean id="converters" class="org.springframework.context.support.ConversionServiceFactoryBean">
<property name="converters">
<bean class="com.hc.controller.PointConverter"></bean>
</property>
</bean>
<mvc:annotation-driven conversion-service="converters"></mvc:annotation-driven>Split by - in the middle
For example: 667-87, it will be formatted as (667, 87)
Encapsulate tostring method in point class, the effect will be obvious
5. Picture upload
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="defaultEncoding" value="UTF-8"></property>
<property name="maxUploadSize" value="2097152"></property>
</bean>Set the default encoding to UTF-8
The maximum upload size is: 1024 * 1024 * 2 = 2097152 2M
<form action="/load.action" method="post" enctype="multipart/form-data">
form upload method is POST
The name of the selection box is the same as the variable name of the MultipartFile parameter of the controller method
file.getOriginalFilename(): picture name
If you need System.currentTimeMillis(), add a time stamp.
Because if a file with the same name is uploaded, the existing one will be overwritten.
file.getSize(): picture size
request.getRealPath("/images"): get the path of images on the server
try catch: Alt + ENTER