Support a subset of String.format in java2dart.

editor/util/plugins/com.google.dart.java2dart/resources/java_core.dart

 library java.core;
 
 import "dart:math" as math;
 import "dart:uri";
 import "dart:collection" show ListBase;
 
 class JavaSystem {
   static int currentTimeMillis() {
     return (new DateTime.now()).millisecondsSinceEpoch;
   }
@@ skipping 112 matching lines @@
   String subSequence(int start, int end) => _content.substring(start, end);
 }
 
 class CharBuffer extends CharSequence {
   CharBuffer(String content) : super(content);
   static CharBuffer wrap(String content) => new CharBuffer(content);
 }
 
 class JavaString {
   static String format(String fmt, List args) {
-    return fmt;
+    var index = 0;
+    return fmt.replaceAllMapped(new RegExp(r'%(.)'), (match) {
+      switch (match.group(1)) {
+        case '%': return '%';
+        case 's':
+          if (index >= args.length) {
+            throw new MissingFormatArgumentException(match.group(0));
+          }
+          return args[index++].toString();
+        default: return match.group(1);
+      }
+    });
   }
 }
 
 /**
  * Very limited printf implementation, supports only %s and %d.
  */
 String _printf(String fmt, List args) {
   StringBuffer sb = new StringBuffer();
   bool markFound = false;
   int argIndex = 0;
@@ skipping 112 matching lines @@
 }
 
 class URISyntaxException implements Exception {
   String toString() => "URISyntaxException";
 }
 
 class IOException implements Exception {
   String toString() => "IOException";
 }
 
+class MissingFormatArgumentException implements Exception {
+  final String s;
+
+  String toString() => "MissingFormatArgumentException: $s";
+
+  MissingFormatArgumentException(this.s);
+}
+
 class ListWrapper<E> extends ListBase<E> implements List<E> {
   List<E> elements = new List<E>();
 
   Iterator<E> get iterator {
     return elements.iterator;
   }
 
   E operator [](int index) {
     return elements[index];
   }
@@ skipping 181 matching lines @@
       }
     } else if (sb.length > newLength) {
       var s = sb.toString().substring(0, newLength);
       sb = new StringBuffer(s);
     }
   }
   void clear() {
     sb = new StringBuffer();
   }
 }