Java Web Application use Sprint Boot Client will appear the HTTP Status 500 error

Answered

Permanently deleted user

Created November 16, 2018 08:19

I create a Sprint Boot project and Sprint Boot Client project (console mode). These connect with no problem. I want to create a Java Web Application with the Spring Boot pom.xml and reference the code of this web(as below) to create three buttons.

How do I call a specific Java method on click/submit event of specific button in JSP?

My button event code as below.

import org.springframework.http.*;
import org.springframework.web.client.RestTemplate;

import java.util.Collections;

public class MyClass {

    public MyClass()
    {

    }

    public void method1()
    {
        System.out.println("method1");
        RestTemplate restTemplate = new RestTemplate();
        org.springframework.http.HttpHeaders headers = new  org.springframework.http.HttpHeaders();
        headers.setAccept(Collections.singletonList( org.springframework.http.MediaType.APPLICATION_JSON));
        String resourceURL = "http://192.168.56.4:8080/run?name=/home/myuser/test";
        org.springframework.http.HttpEntity<String> entity = new  org.springframework.http.HttpEntity<String>(headers);
        org.springframework.http.ResponseEntity<String> response2 = restTemplate.exchange(resourceURL,  org.springframework.http.HttpMethod.GET,entity,String.class);

        if (response2.getStatusCode() ==  org.springframework.http.HttpStatus.OK)
        {
            System.out.println("Hello World");
            System.out.println(response2);
            System.out.println(response2.getBody());
        }
        else
        {
            System.out.println("Error");
        }
    }

    public void method2() {
        //some code
        System.out.println("method2");
    }

    public void method3() {
        //some code
        System.out.println("method3");
    }
}

When I click one of the buttons, the web browser will appear the HTTP Status 500 - Internal Server Error as below.

HTTP Status 500 – Internal Server Error
Type Exception Report

Message Servlet execution threw an exception

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

javax.servlet.ServletException: Servlet execution threw an exception
 org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause

java.lang.NoClassDefFoundError: org/springframework/util/MultiValueMap
 com.mycompany.jsp.MyServlet.doPost(MyServlet.java:15)
 javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
 javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
 org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause

java.lang.ClassNotFoundException: org.springframework.util.MultiValueMap
 org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1328)
 org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1157)
 com.mycompany.jsp.MyServlet.doPost(MyServlet.java:15)
 javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
 javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
 org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Note The full stack trace of the root cause is available in the server logs.

Apache Tomcat/9.0.13

If I comment the Spring Boot code in MyClass' method1, I click any button and there is no error appear.

Does somebody know how to integrate Spring Boot to Java Web Application?

2 comments

Permanently deleted user

Created November 16, 2018 08:43

My pom.xml content is as below:

<?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>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.0.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-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>

    </dependencies>

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

</project>

Yaroslav Bedrov

Created November 19, 2018 12:10

Hello,

Seems needed library is missing from the classpath. Is it possible to provide project example for investigation?

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