为什么我收到java.lang.NullPointerException而不是soap响应？ [英] Why am I receiving java.lang.NullPointerException rather than soap response?

问题描述

我向服务器发送以下请求，当我复制请求并使用SOAPUI时，它显示正确的响应，

I am sending the following request to the server, when I copy the request and use the SOAPUI it shows the correct response,

但是当我使用以下代码时生成并发送它，返回

but when I use the following code to generate and send it, returns

java.lang.NullPointerException

第50行，

sm.writeTo(out);

代码：

SOAPConnectionFactory soapConnectionFactory = SOAPConnectionFactory.newInstance();
SOAPConnection connection = soapConnectionFactory.createConnection();
SOAPFactory soapFactory = SOAPFactory.newInstance();
MessageFactory factory = MessageFactory.newInstance();
SOAPMessage message = factory.createMessage();
SOAPHeader header = message.getSOAPHeader();
SOAPPart soapPart = message.getSOAPPart();
SOAPEnvelope soapEnvelope = soapPart.getEnvelope();        
SOAPBody body = soapEnvelope.getBody();
header.removeNamespaceDeclaration(header.getPrefix());

soapEnvelope.addNamespaceDeclaration("v9", "ADDRESS OF SERVICE");

Name bodyName;
bodyName = soapFactory.createName("User");

SOAPElement getList = body.addChildElement("User", "v9");

Name childName;

getList.addChildElement("name", "v9").addTextNode("Alex");
getList.addChildElement("surname", "v9").addTextNode("Nicroid");   

message.writeTo(System.out); 

URL endpoint = new URL("ENDPOINT ADDRESS OF SERVER");
SOAPMessage response = connection.call(message, endpoint);

connection.close();

SOAPMessage sm = response;

ByteArrayOutputStream out = new ByteArrayOutputStream();

sm.writeTo(out); //java.lang.NullPointerException

System.out.println(out.toString());

Maven

 <url>http://maven.apache.org</url>
  <build>
    <resources>
      <resource>
        <targetPath>META-INF</targetPath>
        <directory>src</directory>
        <includes>
          <include>jax-ws-catalog.xml</include>
          <include>wsdl/**</include>
        </includes>
      </resource>
      <resource>
        <directory>src/main/resources</directory>
      </resource>
    </resources>
    <plugins>
      <plugin>
        <groupId>org.jvnet.jax-ws-commons</groupId>
        <artifactId>jaxws-maven-plugin</artifactId>
        <version>2.2.1</version>
        <dependencies>
          <dependency>
            <groupId>javax.xml</groupId>
            <artifactId>webservices-api</artifactId>
            <version>1.4</version>
          </dependency>
        </dependencies>
        <configuration>
          <sourceDestDir>${project.build.directory}/generated-sources/jaxws-wsimport</sourceDestDir>
          <xnocompile>true</xnocompile>
          <verbose>true</verbose>
          <extension>true</extension>
          <catalog>${basedir}/src/jax-ws-catalog.xml</catalog>
        </configuration>
      </plugin>
    </plugins>
  </build>
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.jdom</groupId>
      <artifactId>jdom</artifactId>
      <version>1.1</version>
      <type>jar</type>
    </dependency>
    <dependency>
      <groupId>com.sun.xml.ws</groupId>
      <artifactId>webservices-rt</artifactId>
      <version>1.4</version>
      <scope>compile</scope>
    </dependency>
  </dependencies>
</project>

推荐答案

如果您在第50行遇到NullPointerException，那是因为 st 为空。那是 connection.call（message，endpoint）; 返回null。

If you are having NullPointerException at line 50 it's because st is null. That is connection.call(message, endpoint); is returning null.

假设您正在使用SOAPConnection的默认实现（com.sun） .xml.internal.messaging.saaj.client.p2p.HttpSOAPConnectionFactory -
见 http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/javax/xml /soap/SOAPConnectionFactory.java - 第47-48行
方法调用（...）只能返回null：

Assuming you are using the default implementation of SOAPConnection (com.sun.xml.internal.messaging.saaj.client.p2p.HttpSOAPConnectionFactory - See http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/javax/xml/soap/SOAPConnectionFactory.java - Lines 47-48) There are just a few reasons method call(...) can return null:

• ，因此收到的响应代码，既不HttpURLConnection.HTTP_INTERNAL_ERROR（500），也不HttpURLConnection.HTTP_OK（200）


• 的响应代码正确但未返回回复消息

请参阅 http://grepcode.com/file/repository.grepcode.com/的java /根/ JDK /的openjdk / 7-B147 / COM /太阳/ XML /内部/消息/ SAAJ /客户端/ P2P / HttpSOAPConnection.java＃HttpSOAPConnection.call％28javax.xml.soap.SOAPMessage％2Cjava.lang.Object％ 29 第281至第341行。

See http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/7-b147/com/sun/xml/internal/messaging/saaj/client/p2p/HttpSOAPConnection.java#HttpSOAPConnection.call%28javax.xml.soap.SOAPMessage%2Cjava.lang.Object%29 Lines 281 to 341.

我无法继续进行分析，因为我无法重现该问题。我建议你下载所涉及的java类的源代码，将它链接到你的调试器并在调试模式下执行它以查看你的用例中实际发生了什么。

I can't go any further with the analysis because I'm not able to reproduce the issue. I suggest you download source code of involved java classes, link it to your debugger and execute it in debug mode to see what is actually happening in your usecase.

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