1, The type of data that can be obtained from the client
- Basic type parameters
- POJO type parameter (JavaBean)
- Array type
2, Method of obtaining data
I. Basic data type - the parameter name of the business method in the controller is consistent with the parameter name sent, and MVC automatically matches the input
- Edit UserController.class in the main java study controller directory and define a method
@RequestMapping("/quick1")
@ResponseBody
public void show1(String name,int age) {
System.out.println(name+age);
}
- Start tomcat and access http://localhost:8080/demo03_ war/quick1? Name = qwe & age = 12, data obtained successfully
II. POJO data type - the parameter passed in is the attribute name of the class, and MVC automatically matches it into an object
- Define a student class. The properties of the class include name and age, and both getter and setter methods are defined
- The request parameter of a method in UserController.class is student type
@RequestMapping("/quick1")
@ResponseBody
public void show1(Student student) {
System.out.println(student);
}
- Start tomcat and access http://localhost:8080/demo03_ war/quick1? Name = qwe & age = 12, MVC successfully encapsulates the data into a Student object
III. array type - automatic matching
- The request parameter of a method in UserController.class is a string array and the name is str
- Start tomcat, pass in continuous parameters whose names are STR, and mvc will be automatically encapsulated into an array. URL: quick1? str=a&str=b&str=c
Ⅳ. Set type - by defining a class in which a list array of student type is defined, the parameter passed in by the client needs to indicate the attribute in the array
- Define a Vo class
public class VO {
private List<Student> vo_list;
public List<Student> getVo_list() {
return vo_list;
}
public void setVo_list(List<Student> vo_list) {
this.vo_list = vo_list;
}
@Override
public String toString() {
return "VO{" +
"vo_list=" + vo_list +
'}';
}
}
- Define controller
@RequestMapping("/quick1")
@ResponseBody
public void show1(VO vo) {
System.out.println(vo);
}
- Define a test.jsp and pass the array through the table tag inside
<form action="${pageContext.request.contextPath}/quick1" method="post">
<input type="text" name="vo_list[0].name" value="qwe"><br/>
<input type="text" name="vo_list[0].age" value="12"><br/>
<input type="text" name="vo_list[1].name" value="asd"><br/>
<input type="text" name="vo_list[1].age" value="13"><br/>
<input type="submit" value="Submit">
</form>
- Open tomcat, visit the jsp/test.jsp page, click the submit button to obtain the data
- Because quick1 needs the data of VO object, VO needs a list array of student type, and the array name is vo_list, so you need to specify consistent array names and attribute values when submitting data
V. collection type - when submitting using ajax, the json specified as contentType is obtained by MVC through @ RequestBody
- Create a new js directory under the webapp directory, and import jquery-3.3.1 into the js directory
- Edit spring-mvc.xml and add jquery
<mvc:resources mapping="/js/**" location="/js/"/> perhaps <mvc:default-servlet-handler/>
- Modify test.jsp
<html>
<head>
<title>Title</title>
<script src="${pageContext.request.contextPath}/js/jquery-3.3.1.min.js"></script>
<script>
var user_list = new Array();
user_list.push({username:"qwe",age:12})
user_list.push({username:"asd",age:13})
$.ajax({
type:"POST",url:"${pageContext.request.contextPath}/quick1",
data:JSON.stringify(vo_list),
contentType:"application/json;charset=utf-8"
});
</script>
</head>
<body>
</body>
</html>
- Accept ajax data with @ RequestBody annotation
@RequestMapping("/quick1")
@ResponseBody
public void show1(@RequestBody List<Student> user_list) {
System.out.println(user_list);
}
Vi. solve the problem of garbled code in Chinese after POST
- Edit web.xml
<filter>
<filter-name>characterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>characterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
VII. Use @ RequestParam annotation to solve the inconsistency between submission parameter name and method parameter
- Modify controller
@RequestMapping("/quick1")
@ResponseBody
public void show1(@RequestParam(value = "username") String name) {
System.out.println(name);
}
- When the page submits the username parameter, MVC converts it to name for encapsulation
3, Get data - Restful
-
graphic
-
Parameters submitted when accessing URL: http://localhost:8080/demo03_war/quick1/zhangsan
-
Modify controller
@RequestMapping("/quick1/{name}")
@ResponseBody
public void show1(@PathVariable(value = "name",required = true) String username) {
System.out.println(username);
}
- Start tomcat access http://localhost:8080/demo03_war/quick1/zhangsan validation data
4, Get data - Custom conversion type
Premise: Although string can be converted to int, date and other data cannot be converted automatically and need to be configured manually
- Create DateConverter.class in the main java study converter directory
public class DateConverter implements Converter<String, Date> {
@Override
public Date convert(String dateStr) {
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
Date date =null;
try {
date = format.parse(dateStr);
} catch (ParseException e) {
e.printStackTrace();
}
return date;
}
}
- Configure spring-mvc.xml
<mvc:annotation-driven conversion-service="conversionService"/>
<bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
<property name="converters">
<list>
<bean class="study.converter.DateConverter"/>
</list>
</property>
</bean>
- Edit controller
@RequestMapping(value = "/quick1")
@ResponseBody
public void show1(Date date) {
System.out.println(date);
}
- Start tomcat and access: quick1?date=2021-10-04