Simplify append substring

src/main/org/apache/tools/ant/DefaultLogger.java

@@ -140,7 +140,7 @@ public class DefaultLogger implements BuildLogger {
             String msg1 = error.toString();
             String msg2 = cause.toString();
             if (msg1.endsWith(msg2)) {
-                m.append(msg1.substring(0, msg1.length() - msg2.length()));
+                m.append(msg1, 0, msg1.length() - msg2.length());
                 error = cause;
             } else {
                 break;

src/main/org/apache/tools/ant/filters/TokenFilter.java

@@ -380,7 +380,7 @@ public class TokenFilter extends BaseFilterReader
             while (found >= 0) {
                 // write everything up to the from
                 if (found > start) {
-                    ret.append(line.substring(start, found));
+                    ret.append(line, start, found);
                 }
 
                 // write the replacement to

src/main/org/apache/tools/ant/taskdefs/KeySubst.java

@@ -177,7 +177,7 @@ public class KeySubst extends Task {
         while ((index = origString.indexOf("${", i)) > -1) {
             key = origString.substring(index + 2, origString.indexOf("}",
                                        index + 3));
-            finalString.append(origString.substring(i, index));
+            finalString.append(origString, i, index);
             if (keys.containsKey(key)) {
                 finalString.append(keys.get(key));
             } else {

src/main/org/apache/tools/ant/types/FilterSet.java

@@ -536,7 +536,7 @@ public class FilterSet extends DataType implements Cloneable {
                     }
                     String token =
                         line.substring(index + beginToken.length(), endIndex);
-                    b.append(line.substring(i, index));
+                    b.append(line, i, index);
                     if (tokens.containsKey(token)) {
                         String value = tokens.get(token);
                         if (recurse && !value.equals(token)) {

src/main/org/apache/tools/ant/util/LayoutPreservingProperties.java

@@ -554,7 +554,7 @@ public class LayoutPreservingProperties extends Properties {
             }
             final int p = forEscaping.indexOf(c);
             if (p != -1) {
-                buffy.append("\\").append(escaped.substring(p, p + 1));
+                buffy.append("\\").append(escaped, p, p + 1);
             } else if (c < 0x0020 || c > 0x007e) {
                 buffy.append(escapeUnicode(c));
             } else {

src/main/org/apache/tools/mail/SmtpResponseReader.java

@@ -57,7 +57,7 @@ public class SmtpResponseReader {
         String line = reader.readLine();
         // CheckStyle:MagicNumber OFF
         if (line != null && line.length() >= 3) {
-            result.append(line.substring(0, 3));
+            result.append(line, 0, 3);
             result.append(" ");
         }
         // CheckStyle:MagicNumber ON