> Yes, StringJoiner is really good at joining Strings (hence the name).
> But it is not very good at joining primitives. Because you have to
> convert each primitive to a String before you can add it.
> StringBuilder does not need to allocate a String when you add a
> primitive.
I've reworked my patch to affect only the spots where we either already have
Strings
or do convertion to String (just like StringBuilder.append(Object) does using
String::valueOf).
Also I've dropped erroneous changes to Atomic*Array (thanks Martin for spotting
this).
Regards,
Sergey Tsypanov
diff --git a/src/java.base/share/classes/java/util/Arrays.java b/src/java.base/share/classes/java/util/Arrays.java
--- a/src/java.base/share/classes/java/util/Arrays.java
+++ b/src/java.base/share/classes/java/util/Arrays.java
@@ -5123,19 +5123,14 @@
public static String toString(Object[] a) {
if (a == null)
return "null";
-
- int iMax = a.length - 1;
- if (iMax == -1)
+ if (a.length == 0)
return "[]";
- StringBuilder b = new StringBuilder();
- b.append('[');
- for (int i = 0; ; i++) {
- b.append(String.valueOf(a[i]));
- if (i == iMax)
- return b.append(']').toString();
- b.append(", ");
+ StringJoiner sj = new StringJoiner(", ", "[", "]");
+ for (Object o : a) {
+ sj.add(String.valueOf(o));
}
+ return sj.toString();
}
/**
diff --git a/src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocationHandler.java b/src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocationHandler.java
--- a/src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocationHandler.java
+++ b/src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocationHandler.java
@@ -309,12 +309,10 @@
* of an annotation.
*/
private static String toSourceString(String s) {
- StringBuilder sb = new StringBuilder();
- sb.append('"');
+ StringJoiner sb = new StringJoiner("", "\"", "\"");
for (int i = 0; i < s.length(); i++) {
- sb.append(quote(s.charAt(i)));
+ sb.add(quote(s.charAt(i)));
}
- sb.append('"');
return sb.toString();
}
diff --git a/src/java.base/share/classes/sun/security/pkcs/SigningCertificateInfo.java b/src/java.base/share/classes/sun/security/pkcs/SigningCertificateInfo.java
--- a/src/java.base/share/classes/sun/security/pkcs/SigningCertificateInfo.java
+++ b/src/java.base/share/classes/sun/security/pkcs/SigningCertificateInfo.java
@@ -26,10 +26,9 @@
package sun.security.pkcs;
import java.io.IOException;
-import java.util.ArrayList;
+import java.util.StringJoiner;
import sun.security.util.HexDumpEncoder;
-import sun.security.util.DerInputStream;
import sun.security.util.DerValue;
import sun.security.x509.GeneralNames;
import sun.security.x509.SerialNumber;
@@ -92,14 +91,10 @@
}
public String toString() {
- StringBuilder sb = new StringBuilder();
- sb.append("[\n");
- for (int i = 0; i < certId.length; i++) {
- sb.append(certId[i].toString());
+ StringJoiner sb = new StringJoiner("", "[\n", "\n]");
+ for (ESSCertId id : certId) {
+ sb.add(id.toString());
}
- // format policies as a string
- sb.append("\n]");
-
return sb.toString();
}
diff --git a/src/java.xml/share/classes/com/sun/org/apache/bcel/internal/classfile/ArrayElementValue.java b/src/java.xml/share/classes/com/sun/org/apache/bcel/internal/classfile/ArrayElementValue.java
--- a/src/java.xml/share/classes/com/sun/org/apache/bcel/internal/classfile/ArrayElementValue.java
+++ b/src/java.xml/share/classes/com/sun/org/apache/bcel/internal/classfile/ArrayElementValue.java
@@ -23,6 +23,7 @@
import java.io.DataOutputStream;
import java.io.IOException;
+import java.util.StringJoiner;
/**
* @since 6.0
@@ -35,16 +36,10 @@
@Override
public String toString()
{
- final StringBuilder sb = new StringBuilder();
- sb.append("{");
- for (int i = 0; i < evalues.length; i++)
- {
- sb.append(evalues[i]);
- if ((i + 1) < evalues.length) {
- sb.append(",");
- }
+ StringJoiner sb = new StringJoiner(",", "{", "}");
+ for (ElementValue evalue : evalues) {
+ sb.add(evalue.stringifyValue());
}
- sb.append("}");
return sb.toString();
}
@@ -71,16 +66,10 @@
@Override
public String stringifyValue()
{
- final StringBuilder sb = new StringBuilder();
- sb.append("[");
- for (int i = 0; i < evalues.length; i++)
- {
- sb.append(evalues[i].stringifyValue());
- if ((i + 1) < evalues.length) {
- sb.append(",");
- }
+ StringJoiner sb = new StringJoiner(",", "[", "]");
+ for (ElementValue evalue : evalues) {
+ sb.add(evalue.stringifyValue());
}
- sb.append("]");
return sb.toString();
}
diff --git a/src/java.xml/share/classes/com/sun/org/apache/bcel/internal/generic/ArrayElementValueGen.java b/src/java.xml/share/classes/com/sun/org/apache/bcel/internal/generic/ArrayElementValueGen.java
--- a/src/java.xml/share/classes/com/sun/org/apache/bcel/internal/generic/ArrayElementValueGen.java
+++ b/src/java.xml/share/classes/com/sun/org/apache/bcel/internal/generic/ArrayElementValueGen.java
@@ -24,7 +24,7 @@
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.ArrayList;
-import java.util.List;
+import java.util.StringJoiner;
import com.sun.org.apache.bcel.internal.classfile.ArrayElementValue;
import com.sun.org.apache.bcel.internal.classfile.ElementValue;
@@ -102,15 +102,10 @@
@Override
public String stringifyValue()
{
- final StringBuilder sb = new StringBuilder();
- sb.append("[");
- String comma = "";
+ StringJoiner sb = new StringJoiner(",", "[", "]");
for (final ElementValueGen element : evalues) {
- sb.append(comma);
- comma = ",";
- sb.append(element.stringifyValue());
+ sb.add(element.stringifyValue());
}
- sb.append("]");
return sb.toString();
}
diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Attribute.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Attribute.java
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Attribute.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Attribute.java
@@ -26,7 +26,7 @@
package com.sun.tools.javac.code;
import java.util.LinkedHashMap;
-import java.util.Map;
+import java.util.StringJoiner;
import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.element.AnnotationValue;
import javax.lang.model.element.AnnotationValueVisitor;
@@ -328,16 +328,10 @@
public void accept(Visitor v) { v.visitArray(this); }
@DefinedBy(Api.LANGUAGE_MODEL)
public String toString() {
- StringBuilder buf = new StringBuilder();
- buf.append('{');
- boolean first = true;
+ StringJoiner buf = new StringJoiner(", ", "{", "}");
for (Attribute value : values) {
- if (!first)
- buf.append(", ");
- first = false;
- buf.append(value);
+ buf.add(String.valueOf(value));
}
- buf.append('}');
return buf.toString();
}
@DefinedBy(Api.LANGUAGE_MODEL)
diff --git a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/soql/JSList.java b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/soql/JSList.java
--- a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/soql/JSList.java
+++ b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/soql/JSList.java
@@ -25,7 +25,6 @@
package sun.jvm.hotspot.utilities.soql;
import java.util.*;
-import sun.jvm.hotspot.oops.*;
/**
This is JavaScript wrapper for Java List.
@@ -94,15 +93,10 @@
}
public String toString() {
- StringBuffer buf = new StringBuffer();
- buf.append('[');
- for (Iterator itr = list.iterator(); itr.hasNext();) {
- buf.append(wrapObject(itr.next()));
- if (itr.hasNext()) {
- buf.append(", ");
- }
- }
- buf.append(']');
+ StringJoiner buf = new StringJoiner(", ", "[", "]");
+ for (Object o : list) {
+ buf.add(String.valueOf(wrapObject(o)));
+ }
return buf.toString();
}
diff --git a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.graph/src/org/graalvm/compiler/graph/NodeClass.java b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.graph/src/org/graalvm/compiler/graph/NodeClass.java
--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.graph/src/org/graalvm/compiler/graph/NodeClass.java
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.graph/src/org/graalvm/compiler/graph/NodeClass.java
@@ -39,9 +39,9 @@
import java.util.ArrayList;
import java.util.Arrays;
import java.util.EnumSet;
-import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Objects;
+import java.util.StringJoiner;
import java.util.concurrent.atomic.AtomicInteger;
import jdk.internal.vm.compiler.collections.EconomicMap;
@@ -1144,20 +1144,10 @@
@Override
public String toString() {
- StringBuilder sb = new StringBuilder();
- Iterator<Node> iterator = iterator();
- boolean first = true;
- sb.append("succs=");
- sb.append('[');
- while (iterator.hasNext()) {
- Node input = iterator.next();
- if (!first) {
- sb.append(", ");
- }
- sb.append(input);
- first = false;
+ StringJoiner sb = new StringJoiner(", ", "succs=[", "]");
+ for (Node input : this) {
+ sb.add(String.valueOf(input));
}
- sb.append(']');
return sb.toString();
}
};
@@ -1178,20 +1168,10 @@
@Override
public String toString() {
- StringBuilder sb = new StringBuilder();
- Iterator<Node> iterator = iterator();
- boolean first = true;
- sb.append("inputs=");
- sb.append('[');
- while (iterator.hasNext()) {
- Node input = iterator.next();
- if (!first) {
- sb.append(", ");
- }
- sb.append(input);
- first = false;
+ StringJoiner sb = new StringJoiner(", ", "inputs=[", "]");
+ for (Node input : this) {
+ sb.add(String.valueOf(input));
}
- sb.append(']');
return sb.toString();
}
};
diff --git a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.graph/src/org/graalvm/compiler/graph/NodeUsageIterable.java b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.graph/src/org/graalvm/compiler/graph/NodeUsageIterable.java
--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.graph/src/org/graalvm/compiler/graph/NodeUsageIterable.java
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.graph/src/org/graalvm/compiler/graph/NodeUsageIterable.java
@@ -26,9 +26,7 @@
import static org.graalvm.compiler.graph.Graph.isModificationCountsEnabled;
-import java.util.Iterator;
-
-import org.graalvm.compiler.graph.iterators.NodeIterable;
+import java.util.StringJoiner;
class NodeUsageIterable implements NodeIterable<Node> {
@@ -69,20 +67,10 @@
@Override
public String toString() {
- StringBuilder sb = new StringBuilder();
- Iterator<Node> iterator = iterator();
- boolean first = true;
- sb.append("usages=");
- sb.append('[');
- while (iterator.hasNext()) {
- Node input = iterator.next();
- if (!first) {
- sb.append(", ");
- }
- sb.append(input);
- first = false;
+ StringJoiner sb = new StringJoiner(", ", "usages=[", "]");
+ for (Node input : this) {
+ sb.add(String.valueOf(input));
}
- sb.append(']');
return sb.toString();
}
}
diff --git a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/phases/aot/EliminateRedundantInitializationPhase.java b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/phases/aot/EliminateRedundantInitializationPhase.java
--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/phases/aot/EliminateRedundantInitializationPhase.java
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/phases/aot/EliminateRedundantInitializationPhase.java
@@ -27,8 +27,8 @@
import static org.graalvm.util.CollectionsUtil.anyMatch;
import java.util.ArrayList;
-import java.util.Iterator;
import java.util.List;
+import java.util.StringJoiner;
import jdk.vm.ci.hotspot.HotSpotMetaspaceConstant;
import jdk.vm.ci.meta.Constant;
@@ -43,7 +43,6 @@
import org.graalvm.compiler.nodes.FixedWithNextNode;
import org.graalvm.compiler.nodes.Invoke;
import org.graalvm.compiler.nodes.StructuredGraph;
-import org.graalvm.compiler.phases.BasePhase;
import org.graalvm.compiler.phases.graph.MergeableState;
import org.graalvm.compiler.phases.graph.PostOrderNodeIterator;
import org.graalvm.compiler.phases.tiers.PhaseContext;
@@ -185,17 +184,10 @@
}
protected static String toString(EconomicSet<ResolvedJavaType> types) {
- StringBuilder b = new StringBuilder();
- b.append("[");
- Iterator<ResolvedJavaType> i = types.iterator();
- while (i.hasNext()) {
- ResolvedJavaType t = i.next();
- b.append(t.toString());
- if (i.hasNext()) {
- b.append(",");
- }
+ StringJoiner b = new StringJoiner(",", "[", "]");
+ for (ResolvedJavaType t : types) {
+ b.add(t.toString());
}
- b.append("]");
return b.toString();
}
diff --git a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/cfg/Block.java b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/cfg/Block.java
--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/cfg/Block.java
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/cfg/Block.java
@@ -25,7 +25,7 @@
package org.graalvm.compiler.nodes.cfg;
import java.util.ArrayList;
-import java.util.Iterator;
+import java.util.StringJoiner;
import org.graalvm.compiler.core.common.cfg.AbstractBlockBase;
import org.graalvm.compiler.core.common.cfg.AbstractControlFlowGraph;
@@ -169,14 +169,11 @@
@Override
public String toString() {
- StringBuilder str = new StringBuilder().append('[');
+ StringJoiner str = new StringJoiner(", ", "[", "]");
for (FixedNode node : this) {
- str.append(node).append(", ");
+ str.add(String.valueOf(node));
}
- if (str.length() > 1) {
- str.setLength(str.length() - 2);
- }
- return str.append(']').toString();
+ return str.toString();
}
};
}
diff --git a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/util/GraphUtil.java b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/util/GraphUtil.java
--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/util/GraphUtil.java
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/util/GraphUtil.java
@@ -26,17 +26,13 @@
import java.util.ArrayList;
import java.util.Arrays;
-import java.util.Collection;
import java.util.Collections;
-import java.util.Iterator;
-import java.util.List;
import java.util.Objects;
-import java.util.function.BiFunction;
+import java.util.StringJoiner;
import jdk.internal.vm.compiler.collections.EconomicMap;
import jdk.internal.vm.compiler.collections.EconomicSet;
import jdk.internal.vm.compiler.collections.Equivalence;
-import jdk.internal.vm.compiler.collections.MapCursor;
import org.graalvm.compiler.bytecode.Bytecode;
import org.graalvm.compiler.code.SourceStackTraceBailoutException;
import org.graalvm.compiler.core.common.spi.ConstantFieldProvider;
@@ -48,7 +44,6 @@
import org.graalvm.compiler.graph.NodeSourcePosition;
import org.graalvm.compiler.graph.NodeStack;
import org.graalvm.compiler.graph.Position;
-import org.graalvm.compiler.graph.iterators.NodeIterable;
import org.graalvm.compiler.graph.spi.SimplifierTool;
import org.graalvm.compiler.nodes.AbstractBeginNode;
import org.graalvm.compiler.nodes.AbstractEndNode;
@@ -605,15 +600,10 @@
* @return A string of the format "[a, b, ...]".
*/
public static String toString(Iterable<?> objects) {
- StringBuilder str = new StringBuilder();
- str.append("[");
+ StringJoiner str = new StringJoiner(", ", "[", "]");
for (Object o : objects) {
- str.append(o).append(", ");
+ str.add(String.valueOf(o));
}
- if (str.length() > 1) {
- str.setLength(str.length() - 2);
- }
- str.append("]");
return str.toString();
}
diff --git a/src/jdk.rmic/share/classes/sun/tools/java/MethodSet.java b/src/jdk.rmic/share/classes/sun/tools/java/MethodSet.java
--- a/src/jdk.rmic/share/classes/sun/tools/java/MethodSet.java
+++ b/src/jdk.rmic/share/classes/sun/tools/java/MethodSet.java
@@ -25,7 +25,13 @@
package sun.tools.java;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.StringJoiner;
/**
* The MethodSet structure is used to store methods for a class.
@@ -259,19 +265,11 @@
* Returns a (big) string representation of this MethodSet
*/
public String toString() {
- int len = size();
- StringBuilder sb = new StringBuilder();
+ StringJoiner sb = new StringJoiner(", ", "{", "}");
Iterator<MemberDefinition> all = iterator();
- sb.append("{");
-
while (all.hasNext()) {
- sb.append(all.next().toString());
- len--;
- if (len > 0) {
- sb.append(", ");
- }
+ sb.add(all.next().toString());
}
- sb.append("}");
return sb.toString();
}
}
diff --git a/src/utils/IdealGraphVisualizer/Data/src/com/sun/hotspot/igv/data/serialization/BinaryParser.java b/src/utils/IdealGraphVisualizer/Data/src/com/sun/hotspot/igv/data/serialization/BinaryParser.java
--- a/src/utils/IdealGraphVisualizer/Data/src/com/sun/hotspot/igv/data/serialization/BinaryParser.java
+++ b/src/utils/IdealGraphVisualizer/Data/src/com/sun/hotspot/igv/data/serialization/BinaryParser.java
@@ -371,7 +371,7 @@
sb.append(buffer.getInt());
if (i < len - 1) {
sb.append(", ");
- }
+ }
}
sb.append(']');
return sb.toString().intern();
@@ -388,7 +388,7 @@
sb.append(buffer.getDouble());
if (i < len - 1) {
sb.append(", ");
- }
+ }
}
sb.append(']');
return sb.toString().intern();
@@ -399,15 +399,11 @@
if (len < 0) {
return "null";
}
- StringBuilder sb = new StringBuilder().append('[');
+ StringJoiner sj = new StringJoiner(", ", "[", "]");
for (int i = 0; i < len; i++) {
- sb.append(readPoolObject(Object.class));
- if (i < len - 1) {
- sb.append(", ");
- }
+ sj.add(String.valueOf(readPoolObject(Object.class)));
}
- sb.append(']');
- return sb.toString().intern();
+ return sj.toString().intern();
}
private <T> T readPoolObject(Class<T> klass) throws IOException {
