java - 将 PowerMock 与嵌入式 Tomcat 结合使用

Question

我正在尝试模拟一个由嵌入式 Tomcat 实例调用的静态方法。这是我的测试类:

@RunWith(PowerMockRunner.class)
@PrepareForTest(ExternalAPI.class)
@PowerMockIgnore({"javax.management.*"})
public class TestExternalAPI
{

    @Before
    public void setup() {
        Tomcat tomcat = new Tomcat();
        tomcat.setPort(8080);
        tomcat.enableNaming();
        tomcat.addWebapp("/app", new File("src/test/webapp").getAbsolutePath());
        tomcat.start();
    }

    @Test
    public void testAPI() {
        mockStatic(ExternalAPI.class);
        when(ExternalAPI.getData()).thenReturn(new Data());

        //call Tomcat triggering the call to ExternalAPI.getData()
    }
}

使用此配置我得到以下异常:

java.lang.NoSuchMethodException: org.apache.catalina.deploy.WebXml addServlet
    at org.apache.tomcat.util.IntrospectionUtils.callMethod1(IntrospectionUtils.java:849)
    at org.apache.tomcat.util.digester.SetNextRule.end(SetNextRule.java:201)
    at org.apache.tomcat.util.digester.Digester.endElement(Digester.java:1060)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(AbstractSAXParser.java:609)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanEndElement(XMLDocumentFragmentScannerImpl.java:1783)
...

现在我想也许我需要告诉 PowerMock 忽略 org.apache.* 包，但后来我得到了这个异常:

java.lang.ClassCastException: com.sun.org.apache.xerces.internal.jaxp.SAXParserFactoryImpl cannot be cast to javax.xml.parsers.SAXParserFactory
    at javax.xml.parsers.FactoryFinder.newInstance(FactoryFinder.java:190)
    ... 54 more

我也尝试过忽略所有 org.* 包，这很有效，但是 ExternalAPI.getData() 方法根本没有被模拟。我想这是因为在这种情况下 Tomcat 实例中的任何东西都没有被模拟，因为我们忽略了那些 org.apache.* 包。

为什么会出现这些异常，我应该如何配置 PowerMock？

编辑:我使用的是 Tomcat 7。如果不使用 PowerMock，测试使用嵌入式 Tomcat 实例运行良好。

Answer 1

我认为在嵌入式模式下使用 tomcat 时，您应该设置所有必需的东西，例如协议(protocol)、生命周期监听器(如果有)、servlet 类、上下文参数...

对我有用的示例代码...

    tomcat = new Tomcat();

    // Trigger loading of catalina.properties
    CatalinaProperties.getProperty("foo");

    File appBase = new File(getTemporaryDirectory(), "webapps");
    if (!appBase.exists() && !appBase.mkdir()) {
        Assert.fail("Unable to create appBase for test");
    }

    String protocol = getProtocol();

    Connector connector = new Connector(protocol);
    // Listen only on localhost
    connector.setAttribute("address",
    InetAddress.getByName("localhost").getHostAddress());
    // Use random free port
    connector.setPort(0);
    // Mainly set to reduce timeouts during async tests
    connector.setAttribute("connectionTimeout", "3000");
    tomcat.getService().addConnector(connector);
    tomcat.setConnector(connector);

    // Add AprLifecycleListener if we are using the Apr connector
    if (protocol.contains("Apr")) {
        StandardServer server = (StandardServer) tomcat.getServer();
        AprLifecycleListener listener = new AprLifecycleListener();
        listener.setSSLRandomSeed("/dev/urandom");
        server.addLifecycleListener(listener);
        connector.setAttribute("pollerThreadCount", Integer.valueOf(1));
    }

    File catalinaBase = getTemporaryDirectory();
    tomcat.setBaseDir(catalinaBase.getAbsolutePath());
    tomcat.getHost().setAppBase(appBase.getAbsolutePath());

    System.setProperty("org.apache.catalina.startup.EXIT_ON_INIT_FAILURE", "true");

    Context ctx = tomcat.addContext(getContext(), appBase.getAbsolutePath());
    ctx.setParentClassLoader(EmbeddedTomcatTestBase.class.getClassLoader());
    //Set execution independent of current thread context classloader (compatibility with exec:java mojo)

    Wrapper w = Tomcat.addServlet(ctx, "ServletName", ServletClass.class.getName());
    w.setLoadOnStartup(1);
    w.addMapping("/ServletURI/*");
    w.addMapping("/ServletURI");
    w.addInitParameter("StatusPage", "/diagnostic/status.jsp");


    Wrapper w1 = Tomcat.addServlet(ctx, "statusJSP", JspServlet.class.getName());
    w1.addMapping("/diagnostic/status.jsp");

    Wrapper w3 = Tomcat.addServlet(ctx, "errorJSP", JspServlet.class.getName());
    w3.addMapping("/diagnostic/error.jsp");


    ctx.addParameter("EmbeddedMode", "true");

    ctx.addApplicationListener(ServletContextListnereClass.class.getName());

    ContextConfig contextConfig = new ContextConfig();
    ctx.addLifecycleListener(contextConfig);

    Tomcat.initWebappDefaults(ctx);
    tomcat.start();


   // initialize your engine / invoke any java methods of your interest here..