HADOOP-7749. Add a NetUtils createSocketAddr call which provides more help in exception messages. Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1187103 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -486,6 +486,9 @@ Release 0.23.0 - Unreleased
     HADOOP-7705. Add a log4j back end that can push out JSON data,
     one per line. (stevel)
 
+    HADOOP-7749. Add a NetUtils createSocketAddr call which provides more
+    help in exception messages. (todd)
+
   OPTIMIZATIONS
   
     HADOOP-7333. Performance improvement in PureJavaCrc32. (Eric Caspole

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/NetUtils.java

@@ -150,12 +150,38 @@ public class NetUtils {
    */
   public static InetSocketAddress createSocketAddr(String target,
                                                    int defaultPort) {
+    return createSocketAddr(target, defaultPort, null);
+  }
+
+  /**
+   * Create an InetSocketAddress from the given target string and
+   * default port. If the string cannot be parsed correctly, the
+   * <code>configName</code> parameter is used as part of the
+   * exception message, allowing the user to better diagnose
+   * the misconfiguration.
+   *
+   * @param target a string of either "host" or "host:port"
+   * @param defaultPort the default port if <code>target</code> does not
+   *                    include a port number
+   * @param configName the name of the configuration from which
+   *                   <code>target</code> was loaded. This is used in the
+   *                   exception message in the case that parsing fails. 
+   */
+  public static InetSocketAddress createSocketAddr(String target,
+                                                   int defaultPort,
+                                                   String configName) {
+    String helpText = "";
+    if (configName != null) {
+      helpText = " (configuration property '" + configName + "')";
+    }
     if (target == null) {
-      throw new IllegalArgumentException("Target address cannot be null.");
+      throw new IllegalArgumentException("Target address cannot be null." +
+          helpText);
     }
     int colonIndex = target.indexOf(':');
     if (colonIndex < 0 && defaultPort == -1) {
-      throw new RuntimeException("Not a host:port pair: " + target);
+      throw new RuntimeException("Not a host:port pair: " + target +
+          helpText);
     }
     String hostname;
     int port = -1;
@@ -165,7 +191,14 @@ public class NetUtils {
       } else {
         // must be the old style <host>:<port>
         hostname = target.substring(0, colonIndex);
-        port = Integer.parseInt(target.substring(colonIndex + 1));
+        String portStr = target.substring(colonIndex + 1);
+        try {
+          port = Integer.parseInt(portStr);
+        } catch (NumberFormatException nfe) {
+          throw new IllegalArgumentException(
+              "Can't parse port '" + portStr + "'"
+              + helpText);
+        }
       }
     } else {
       // a new uri

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/net/TestNetUtils.java

@@ -163,6 +163,27 @@ public class TestNetUtils {
     assertRemoteDetailsIncluded(wrapped);
     assertInException(wrapped, "/UnknownHost");
   }
+  
+  @Test
+  public void testCreateSocketAddress() throws Throwable {
+    InetSocketAddress addr = NetUtils.createSocketAddr(
+        "127.0.0.1:12345", 1000, "myconfig");
+    assertEquals("127.0.0.1", addr.getAddress().getHostAddress());
+    assertEquals(12345, addr.getPort());
+    
+    addr = NetUtils.createSocketAddr(
+        "127.0.0.1", 1000, "myconfig");
+    assertEquals("127.0.0.1", addr.getAddress().getHostAddress());
+    assertEquals(1000, addr.getPort());
+
+    try {
+      addr = NetUtils.createSocketAddr(
+          "127.0.0.1:blahblah", 1000, "myconfig");
+      fail("Should have failed to parse bad port");
+    } catch (IllegalArgumentException iae) {
+      assertInException(iae, "myconfig");
+    }
+  }
 
   private void assertRemoteDetailsIncluded(IOException wrapped)
       throws Throwable {