用浏览器来查看Tomcat的运行状态：
配置Tomcat的管理用户和权限。
打开%Tomcat_Home%/conf/目录下的tomcat-user.xml文件，配置以下内容：
<role rolename="manager-status"/>
<role rolename="manager"/>
<role rolename="manager-jmx"/>
<role rolename="manager-gui"/>
<role rolename="manager-script"/>
<role rolename="admin"/>
<user username="tomcat" password="tomcat" roles="tomcat"/>
<user username="admin" password="tomcat" roles="manager,manager-gui,admin,manager-status,manager-jmx,manager-script"/>
此时可通过admin用户来访问tomcat的状态，在浏览器地址中输入：
http://localhost:8080/manager/status?XML=true
输入用户名：admin,密码：tomcat. 出现以下页面，即Tomcat的运行状态。
或者可以直接访问：
http://admin:tomcat[@localhost](http://my.oschina.net/u/570656) :8080/manager/status?XML=true
Java程序获取Tomcat运行状态：
根据上面的思路，可以通过URL来获取Tomcat manager返回的信息，再解析这个信息就可以了，参考cacti的监控方式中，用perl编写的监控模板也是如此，如下：
my $host = shift;
my $username = shift;
my $password = shift;
my $connector = shift or &usage;
my $url = "http://$username:$password"."\@$host/manager/status?XML=true";
my $xml = `GET $url`;
my $status = XMLin($xml);
因此Java也可参考此方法：
@Test
public void test1() throws IOException {
URL url = null;
InputStream is = null;
StringBuffer resultBuffer = new StringBuffer();
BufferedReader breader = null;
try {
url = new URL(
"http://admin:tomcat@localhost:8080/manager/status?XML=true");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
is = conn.getInputStream();
breader = new BufferedReader(new InputStreamReader(is));
String line = "";
while ((line = breader.readLine()) != null) {
resultBuffer.append(line);
}
} catch (MalformedURLException e) {
e.printStackTrace();
} finally {
if (breader != null)
breader.close();
if (is != null)
is.close();
}
System.out.println(resultBuffer.toString());
}
运行时出现如下错误：
java.io.IOException: Server returned HTTP response code: 401 for URL: http://admin:tomcat@localhost:8080/manager/status?XML=true
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1625)
at com.merit.monitor.tomcat.TestTomcatStatus.test1(TestTomcatStatus.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
出错原因可以去stackoverview上查看，这里直接给出正确的解决方法：
1、编写获取Tomcat状态的字符串方法：
/**
* @Description: 获取指定URL的内容
* @Version1.0 2014-7-23 下午02:18:22 by xuqiang（xuqiang@merit.com）创建
* @param tempurl url地址
* @param username tomcat 管理用户名
* @param password tomcat 管理用户密码
* @return
* @throws IOException
*/
public static String getHtmlContext(String tempurl, String username, String password) throws IOException {
URL url = null;
BufferedReader breader = null;
InputStream is = null;
StringBuffer resultBuffer = new StringBuffer();
try {
url = new URL(tempurl);
String userPassword = username + ":" + password;
String encoding = new sun.misc.BASE64Encoder().encode (userPassword.getBytes());//在classpath中添加rt.jar包，在%java_home%/jre/lib/rt.jar
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestProperty("Authorization", "Basic " + encoding);
is = conn.getInputStream();
breader = new BufferedReader(new InputStreamReader(is));
String line = "";
while ((line = breader.readLine()) != null) {
resultBuffer.append(line);
}
} catch (MalformedURLException e) {
e.printStackTrace();
} finally {
if(breader != null)
breader.close();
if(is != null)
is.close();
}
return resultBuffer.toString();
}
2、编写测试方法：
@Test
public void test() {
String result = "";
Document document = null;//引入org.dom4j包
try {
result = GetHtmlContext.getHtmlContext("http://localhost:8080/manager/status?XML=true", "admin", "tomcat");
document = DocumentHelper.parseText(result);//将字符串转化为XML的Document
} catch (IOException e) {
e.printStackTrace();
} catch (DocumentException e) {
e.printStackTrace();
}
System.out.println(document.asXML());
}
运行junit,正常打印监控状态的XML格式内容。这样就可以解析XML Dom的值获取Tomcat的运行状态。
