尝试设置 Spark REST 示例时出错

Question

我正在尝试按照此处所述设置简单的 Spark REST 示例： http://sparkjava.com/documentation.html

我收到这个错误：

[qtp346024113-15] WARN org.eclipse.jetty.server.HttpChannel - //localhost:4567/hello
java.lang.NoSuchMethodError:       javax.servlet.http.HttpServletResponse.getHeaders(Ljava/lang/String;)Ljava/util/Collection;
at spark.utils.GzipUtils.checkAndWrap(GzipUtils.java:64)
at spark.webserver.MatcherFilter.doFilter(MatcherFilter.java:251)
at spark.webserver.JettyHandler.doHandle(JettyHandler.java:61)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:189)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:119)
at org.eclipse.jetty.server.Server.handle(Server.java:517)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:308)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:242)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:261)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:95)
at org.eclipse.jetty.io.SelectChannelEndPoint.run(SelectChannelEndPoint.java:75)
at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.produceAndRun(ExecuteProduceConsume.java:213)
at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.run(ExecuteProduceConsume.java:147)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:654)
at org.eclipse.jetty.util.thread.QueuedThreadPool.run(QueuedThreadPool.java:572)
at java.lang.Thread.run(Thread.java:745)

看起来类路径有问题，但我不知道缺少什么依赖项。

我的 pom.xml for Spark 中的依赖如下：

 <dependency>
        <groupId>org.eclipse.jetty</groupId>
        <artifactId>jetty-server</artifactId>
        <version>9.3.6.v20151106</version>
    </dependency>


  <dependency>
        <groupId>org.eclipse.jetty</groupId>
        <artifactId>jetty-http</artifactId>
        <version>9.3.6.v20151106</version>
    </dependency>

  <dependency>
        <groupId>org.eclipse.jetty</groupId>
        <artifactId>jetty-util</artifactId>
        <version>9.3.6.v20151106</version>
    </dependency>
  <dependency>
        <groupId>org.eclipse.jetty</groupId>
        <artifactId>jetty-io</artifactId>
        <version>9.3.6.v20151106</version>
    </dependency>
    <dependency>
        <groupId>org.eclipse.jetty.websocket</groupId>
        <artifactId>websocket-server</artifactId>
        <version>9.3.3.v20150827</version>
    </dependency>

<dependency>
   <groupId>org.eclipse.jetty.websocket</groupId>
   <artifactId>websocket-servlet</artifactId>
   <version>9.3.3.v20150827</version>
</dependency>

代码：

package com.hello.rest.api;

 import static spark.Spark.*;

public class RestAPI {

public RestAPI() {

}


public static void main(String[] args) {
    System.out.println("Processing hello");
    get("/hello", (req, res) -> "Hello World");
}


}

Answer 1

如错误所示，getHeaders 方法在调用的 HttpServletResponse class 中不存在。

从 Servlet 3.0 开始就存在这个方法。

确保您的 class 路径不包含旧版本的 Servlet API，其中包括 class javax.servlet.http.HttpServletResponse .

此外，也许您的某个依赖项包含它的旧版本。

尝试设置 Spark REST 示例时出错

Error trying to set up Spark REST example

java

rest

spark-java