Binding request parameters
Binding mechanism
- Form submission data is k = v format, such as username = haha & password = 123
- SpringMVC parameter binding process parameter request to submit a form, the method in the controller as a parameter bundling
- Requirements: submit the form name and parameter names are the same
Supported data types
Basic data types, and strings
Requirements: submit the form name and parameter names are the same
For example:
param.jsp
<a href="param/testParam?username=hehe&password=123">RequestMapping注解</a>ParamController
@Controller
@RequestMapping("/param")
public class ParamController {
// 基本数据类型
@RequestMapping("/testParam")
public String testParam(String username,String password){
System.out.println("基本数据类型");
System.out.println("用户名："+username);
System.out.println("密码："+password);
return "success";
}
}Entity type (JavaBean)
name must be the same as the bean property name;
Construction of an entity class
public class Account implements Serializable {
private String username;
private String password;
private Double money;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public Double getMoney() {
return money;
}
public void setMoney(Double money) {
this.money = money;
}
@Override
public String toString() {
return "Account{" +
"username='" + username + '\'' +
", password='" + password + '\'' +
", money=" + money +
'}';
}
}Controller
//请求参数绑定把数据封装到JavaBean的类中
@RequestMapping("/saveAccount")
public String saveAccount(Account account){
System.out.println("执行了...");
System.out.println(account);
return "success";
}Output
Chinese garbled solve the problem, the configuration in web.xml
<!--配置解决中文乱码的过滤器-->
<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>If you have User Account type in, before we need to configure a User class
public class User implements Serializable {
private String uname;
private Integer age;
public String getUname() {
return uname;
}
public void setUname(String uname) {
this.uname = uname;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "User{" +
"uname='" + uname + '\'' +
", age=" + age +
'}';
}
}Account class
public class Account implements Serializable {
private String username;
private String password;
private Double money;
private User user;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public Double getMoney() {
return money;
}
public void setMoney(Double money) {
this.money = money;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
@Override
public String toString() {
return "Account{" +
"username='" + username + '\'' +
", password='" + password + '\'' +
", money=" + money +
", user=" + user +
'}';
}
}params.jsp file
<form action="param/saveAccount" method="post">
姓名：<input type="text" name="username" /><br/>
密码：<input type="text" name="password" /><br/>
金额：<input type="text" name="money" /><br/>
用户姓名：<input type="text" name="user.uname" /><br/>
用户年龄：<input type="text" name="user.age" /><br/>
<input type="submit" value="提交" />
</form>
Request parameters bound to the method, the same method
Output:
Aggregate data type (List, map)
public class Account implements Serializable {
private String username;
private String password;
private Double money;
private List<User> list;
private Map<String,User> map;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public Double getMoney() {
return money;
}
public void setMoney(Double money) {
this.money = money;
}
public List<User> getList() {
return list;
}
public void setList(List<User> list) {
this.list = list;
}
public Map<String, User> getMap() {
return map;
}
public void setMap(Map<String, User> map) {
this.map = map;
}
@Override
public String toString() {
return "Account{" +
"username='" + username + '\'' +
", password='" + password + '\'' +
", money=" + money +
", list=" + list +
", map=" + map +
'}';
}
}params.jsp file
<!--把数据封装到Account类中,类中存在list和map集合-->
<form action="param/saveAccount" method="post">
姓名：<input type="text" name="username" /><br/>
密码：<input type="text" name="password" /><br/>
金额：<input type="text" name="money" /><br/>
用户姓名：<input type="text" name="list[0].uname" /><br/>
用户年龄：<input type="text" name="list[0].age" /><br/>
用户姓名：<input type="text" name="map['one'].uname" /><br/>
用户年龄：<input type="text" name="map['one'].age" /><br/>
<input type="submit" value="提交" />
</form>Output
Custom type converter
Any form submission data type is a string of all types, but the background definition of type Integer, the data may be on the package, the internal frame Spring default data type conversion.
If you want to customize the data type conversion can be achieved Converter interface.
Add a new user class attribute date
public class User implements Serializable { private String uname; private Integer age; private Date date; public String getUname() { return uname; } public void setUname(String uname) { this.uname = uname; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public Date getDate() { return date; } public void setDate(Date date) { this.date = date; } @Override public String toString() { return "User{" + "uname='" + uname + '\'' + ", age=" + age + ", date=" + date + '}'; } }Forms
<form action="param/saveUser" method="post"> 用户姓名：<input type="text" name="uname" /><br/> 用户年龄：<input type="text" name="age" /><br/> 出生日期：<input type="text" name="date"/><br/> <input type="submit" value="提交" /> </form>Method of binding request parameters
@RequestMapping("/saveUser") public String saveUser(User user){ System.out.println("user保存了"); System.out.println(user); return "success"; }Enter the page
Output:
Page input format issue, 400 error occurs.
Solution:
Custom type converter StringToDateConverter
public class StringToDateConverter implements Converter<String,Date> {
/**
* String source 传入进来字符串
* @param source
* @return
*/
public Date convert(String source) {
// 判断
if(source == null){
throw new RuntimeException("请您传入数据");
}
DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
try {
// 把字符串转换日期
return df.parse(source);
} catch (Exception e) {
throw new RuntimeException("数据类型转换出现错误");
}
}
}In springmvc.xml configuration file is custom type converter
<!--配置自定义类型转换器-->
<bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
<property name="converters">
<set>
<bean class="com.ben.utils.StringToDateConverter"/>
</set>
</property>
</bean>
<!-- 开启SpringMVC框架注解的支持 -->
<mvc:annotation-driven conversion-service="conversionService"/>Output
