Ajax post 到 Spring MVC 控制器导致 "Requested resource is unavailable" 错误

Question

我一直在努力让这段代码起作用。我刚开始使用 Spring MVC（我对网络开发还比较陌生——我的背景是 GUI dev/science），但我认为可能会触发错误，因为链接 [=我的 jsp 中的 54=] 代码到 Spring 控制器。几天来，我一直在努力使它正常工作，但都没有成功，而且我已经尝试了该论坛上发帖人提出的所有建议，但都遇到了类似的问题——但无济于事。因此，我非常感谢您的意见。该项目正在使用 Netbeans、Tomcat 8、Maven、Spring MVC 和 Jquery.

进行开发

projectDashboard.jsp（在WEB-INF/views）：

<div class="col-lg-8 col-md-8 col-sm-8">
    <div id="projectForm">                                   
        <div class="form-group">               
            <input id="name" name="name" type="text" class="form-control" placeholder="Project name (50 characters or less)"/>
            <textarea id="description" name="description" class="form-control" placeholder="Project Description (200 characters or less)"></textarea>                                
        </div>       
        <div class="form-group">             
            <input class="btn btn-primary pull-right" id="createProjectButton" value="Create" type="button"/>                    
        </div>                       
    </div>                    
</div>

JQuery:

<script>
        $(document).ready(function(){
            $("#createProjectButton").on("click", function(){      
                var projectJson = {
                    "name":$("#name").val(),
                    "description":$("#description").val()
                };                     
                $.ajax({
                    type: "POST",
                    url: "/ProgressManagerOnline/projectDashboard",
                    data: JSON.stringify(projectJson), 
                    contentType: "application/json; charset=utf-8",
                    dataType: "json"
                });                       
            });
        });            
</script>

ProjectDashboard.java（src/main/java 中的Spring MVC 控制器class）：

@RequestMapping(value = "/projectDashboard", method = RequestMethod.POST)
public String saveProject(@RequestBody Project project) throws Exception {
    return "OK";
}

appconfig中的相关代码-mvc.xml:

<mvc:annotation-driven/>    
<mvc:view-controller path="/" view-name="login"/> //home web page - login.jsp

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix">
        <value>/WEB-INF/views/</value>
    </property>
    <property name="suffix">
        <value>.jsp</value>
    </property>
</bean>

Maven pom.xml 包括：

<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.8.5</version>
</dependency> 
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.8.5</version>
</dependency>

Tomcat context.xml:

<?xml version="1.0" encoding="UTF-8"?>
<Context path="/ProgressManagerOnline"/>

Firefox Web 控制台中的错误：

The requested resource is not available. (404 error)

我的Project.java:

@Entity
@Table(name = "projects")
public class Project implements Serializable {

    private Long id;
    private String name;
    private String description;    
    private java.util.Date dateCreated;

    public Project(){};

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    public Long getId() {
        return id;
    }

    public void setId(Long id){
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    @Column(name = "dateCreated", columnDefinition="DATETIME")
    @Temporal(TemporalType.TIMESTAMP)
    public Date getDateCreated() {
        return dateCreated;
    }

    public void setDateCreated(Date dateCreated) {
        this.dateCreated = dateCreated;
    }    
}

我已经在这里好几天了，并尝试了在这个论坛和其他论坛上发布的每一个建议。

非常感谢任何能提供帮助的人。

Answer 1

我猜你的应用程序中缺少一些配置。

您需要将 json 自动转换为 java 对象，

@RequestBody Project project

因此您需要添加 json 转换器，因此请查看文档：http://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/http/converter/json/MappingJackson2HttpMessageConverter.html

在您的配置上下文 xml 中添加以下内容，并在您的 pom.xml、

中添加所需的依赖项

<!-- Configure bean to convert JSON to POJO and vice versa -->
    <beans:bean id="jsonMessageConverter" class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" />

    <!-- Configure to plugin JSON as request and response in method handler -->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
    <property name="messageConverters">
        <list>
            <ref bean="jsonMessageConverter"/>
        </list>
    </property>
</bean>

Answer 2

(代表OP发表).

TechBreak 建议的解决方案有效 - 我在 pom.xml 中缺少 Spring 上下文依赖项，在 xml 中缺少额外配置：

<!-- Configure bean to convert JSON to POJO and vice versa -->
<bean id="jsonMessageConverter" class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" />

<!-- Configure to plugin JSON as request and response in method handler -->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
    <property name="messageConverters">
        <list>
            <ref bean="jsonMessageConverter"/>
        </list>
    </property>
</bean>

服务器重启后

mvn clean install

干杯。

Ajax post 到 Spring MVC 控制器导致 "Requested resource is unavailable" 错误

Ajax post to Spring MVC controller results in "Requested resource is unavailable" error

java

jquery

maven

spring-mvc

tomcat8