如何使用Spring Boot從URL獲取傳遞的查詢字符串值

Question

我正在嘗試從url查詢字符串中獲取contentid值。

例如： http://localhost:8080/app?contentid=10

我想得到的contentid的值是：從我的spring控制器中的上述url的10，我怎么能得到這個？

請注意，如果我在那里傳遞任何值（例如10、50,100、200，...等-我可以輸入或傳遞任何數字到url ），那么無論我傳遞給contentid ，該值都應進入我的控制器（ System.out.println(contentid); ）。

當前，單擊“提交”按鈕后，出現以下錯誤：

http://localhost:8080/app?contentid=

Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

There was an unexpected error (type=Bad Request, status=400).
Validation failed for object='testData'. Error count: 1

我在STS控制台中進入下方。

2018-02-05 13:09:45.186  INFO 8428 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet 'dispatcherServlet'
2018-02-05 13:09:45.187  INFO 8428 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started
2018-02-05 13:09:45.231  INFO 8428 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 44 ms

控制器：

package com.example.demo;

import java.util.concurrent.ThreadLocalRandom;
import javax.servlet.http.HttpServletRequest;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;

@Controller
public class MyController {

    @GetMapping("/app")
    public String getApp(Model model) {
        return "app";
    }

    @PostMapping("/app")
    public String postApp(@RequestParam(required=false) Integer contentid, @ModelAttribute TestData testData, Model model, HttpServletRequest request) {
        System.out.println(contentid);
        if(contentid == null) {
            contentid = ThreadLocalRandom.current().nextInt(0, 100 + 1);
        }
        model.addAttribute("contentid",contentid);
        return "app";
    }
}

TestData.java：

package com.example.demo;
import java.io.Serializable; 
public class TestData implements Serializable { 
private static final long serialVersionUID = 1L; 
private String firstname; 
private String secondname; 
private int contentid; 

public TestData() { 
} 

//setters and getters

public TestData(String firstname, String secondname, int contentid) { 
this.firstname = firstname; 
this.secondname = secondname; 
this.contentid = contentid; 
} 

@Override 
public String toString() { 
return String.format("TestData[firstname=%s, secondname=%s, contentid=%d]", firstname, secondname, contentid); 
} 

}

app.html：

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:th="http://www.thymeleaf.org"
    xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity4">
<head>

<title></title>

</head>
<body>

<th:block th:if="${contentid != null}">
<div th:text="${'contentId: ' + contentid}"></div>
</th:block>

    <form action="#" th:action="@{/app(contentid=${contentid})}" th:object="${TestData}"
        method="post">
        <div class="form-group">
            <label for="firstname">First Name: </label>
            <input type="text" class="form-control" id="firstname"
                name="firstname" />
        </div>
        <div class="form-group">
            <label for="secondname">Second Name:</label>
            <input type="text" class="form-control" id="secondname"
                name="secondname" />
        </div>
        <button type="submit" value="Submit">Submit</button>
    </form>
</body>
</html>

pom.xml：

    <?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>MySpringBootApp-2</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>MySpringBootApp-2</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
        <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

Answer 1

TestData.java有問題。 int contentId不能為null。 將其更改為Integer contentId 。

如何使用Spring Boot從URL獲取傳遞的查詢字符串值

問題描述

1 個解決方案

解決方案1
0 2018-02-10 15:14:00

如何使用Spring Boot從URL獲取傳遞的查詢字符串值

問題描述

1 個解決方案

解決方案1 0 2018-02-10 15:14:00

解決方案1
0 2018-02-10 15:14:00