Question

如何在win7下的eclipse中调试Hadoop2.2.0的程序

Answer 1

eclipse中调试Hadoop2.2.0的程序的方法：
本地程序要check hadoop运行的环境:
private static String checkHadoopHome() {
// first check the Dflag hadoop.home.dir with JVM scope
//System.setProperty("hadoop.home.dir", "...");
String home = System.getProperty("hadoop.home.dir");

// fall back to the system/user-global env variable
if (home == null) {
home = System.getenv("HADOOP_HOME");
}

try {
// couldn't find either setting for hadoop's home directory
if (home == null) {
throw new IOException("HADOOP_HOME or hadoop.home.dir are not set.");
}

if (home.startsWith("\"") && home.endsWith("\"")) {
home = home.substring(1, home.length()-1);
}

// check that the home setting is actually a directory that exists
File homedir = new File(home);
if (!homedir.isAbsolute() || !homedir.exists() || !homedir.isDirectory()) {
throw new IOException("Hadoop home directory " + homedir
+ " does not exist, is not a directory, or is not an absolute path.");
}

home = homedir.getCanonicalPath();

} catch (IOException ioe) {
if (LOG.isDebugEnabled()) {
LOG.debug("Failed to detect a valid hadoop home directory", ioe);
}
home = null;
}
//固定本机的hadoop地址
home="D:\\hadoop-2.2.0";
return home;
}
2、点击run as就可以直接调试了 。

Answer 2

　　如何eclipse中调试hadoop2.2.0,如果你使用的还是hadoop1.x的版本，那么，也没事，散仙在以前的博客里，也写过eclipse调试1.x的hadoop程序，两者最大的不同之处在于使用的eclipse插件不同，hadoop2.x与hadoop1.x的API，不太一致，所以插件也不一样，我们只需要使用分别对应的插件即可.
　　方法如下：

　　进入wordpress后台，Jetpack，点分享的配置，选择 Add a new service，
　　server name 一定要写英文不能写中文，不然就崩溃了，如douban，
　　private static String checkHadoopHome() {

　　// first check the Dflag hadoop.home.dir with JVM scope
　　//System.setProperty("hadoop.home.dir", "...");
　　String home = System.getProperty("hadoop.home.dir");

　　// fall back to the system/user-global env variable
　　if (home == null) {
　　home = System.getenv("HADOOP_HOME");
　　}

　　try {
　　// couldn't find either setting for hadoop's home directory
　　if (home == null) {
　　throw new IOException("HADOOP_HOME or hadoop.home.dir are not set.");
　　}

　　if (home.startsWith("\"") && home.endsWith("\"")) {
　　home = home.substring(1, home.length()-1);
　　}

　　// check that the home setting is actually a directory that exists
　　File homedir = new File(home);
　　if (!homedir.isAbsolute() || !homedir.exists() || !homedir.isDirectory()) {
　　throw new IOException("Hadoop home directory " + homedir
　　+ " does not exist, is not a directory, or is not an absolute path.");
　　}

　　home = homedir.getCanonicalPath();

　　} catch (IOException ioe) {
　　if (LOG.isDebugEnabled()) {
　　LOG.debug("Failed to detect a valid hadoop home directory", ioe);
　　}
　　home = null;
　　}
　　//固定本机的hadoop地址
　　home="D:\\hadoop-2.2.0";
　　return home;
　　}

　　转载，仅供参考。

Answer 3

private static String checkHadoopHome() {

// first check the Dflag hadoop.home.dir with JVM scope
//System.setProperty("hadoop.home.dir", "...");
String home = System.getProperty("hadoop.home.dir");

// fall back to the system/user-global env variable
if (home == null) {
home = System.getenv("HADOOP_HOME");
}

try {
// couldn't find either setting for hadoop's home directory
if (home == null) {
throw new IOException("HADOOP_HOME or hadoop.home.dir are not set.");
}

if (home.startsWith("\"") && home.endsWith("\"")) {
home = home.substring(1, home.length()-1);
}

// check that the home setting is actually a directory that exists
File homedir = new File(home);
if (!homedir.isAbsolute() || !homedir.exists() || !homedir.isDirectory()) {
throw new IOException("Hadoop home directory " + homedir
+ " does not exist, is not a directory, or is not an absolute path.");
}

home = homedir.getCanonicalPath();

} catch (IOException ioe) {
if (LOG.isDebugEnabled()) {
LOG.debug("Failed to detect a valid hadoop home directory", ioe);
}
home = null;
}
//固定本机hadoop址
home="D:\\hadoop-2.2.0";
return home;
}