enjoy 3.3 release ^_^

src/main/java/com/jfinal/template/io/FastStringWriter.java

@@ -0,0 +1,120 @@
+/**
+ * Copyright (c) 2011-2017, James Zhan 詹波 (jfinal@126.com).
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.jfinal.template.io;
+
+import java.io.Writer;
+
+/**
+ * FastStringWriter
+ * 
+ * <pre>
+ * 由 JDK 中 StringWriter 改造而来，在其基础之上做了如下改变：
+ * 1：StringBuffer 属性改为 StringBuilder，避免了前者的 synchronized 操作
+ * 2：添加了 MAX_SIZE 属性
+ * 3：去掉了 close() 方法声明中的 throws IOException，并添加了代码，原先该方法中无任何代码
+ * </pre>
+ */
+public class FastStringWriter extends Writer {
+	
+	private StringBuilder buf;
+	
+    public FastStringWriter() {
+        buf = new StringBuilder();
+    }
+    
+    public FastStringWriter(int initialSize) {
+        if (initialSize < 0) {
+            throw new IllegalArgumentException("Negative buffer size");
+        }
+        buf = new StringBuilder(initialSize);
+    }
+    
+    public void write(int c) {
+        buf.append((char) c);
+    }
+    
+    public void write(char cbuf[], int off, int len) {
+        if ((off < 0) || (off > cbuf.length) || (len < 0) ||
+            ((off + len) > cbuf.length) || ((off + len) < 0)) {
+            throw new IndexOutOfBoundsException();
+        } else if (len == 0) {
+            return;
+        }
+        buf.append(cbuf, off, len);
+    }
+    
+    public void write(String str) {
+        buf.append(str);
+    }
+    
+    public void write(String str, int off, int len)  {
+        buf.append(str.substring(off, off + len));
+    }
+    
+    public FastStringWriter append(CharSequence csq) {
+        if (csq == null) {
+            write("null");
+        } else {
+            write(csq.toString());
+        }
+        return this;
+    }
+    
+    public FastStringWriter append(CharSequence csq, int start, int end) {
+        CharSequence cs = (csq == null ? "null" : csq);
+        write(cs.subSequence(start, end).toString());
+        return this;
+    }
+    
+    public FastStringWriter append(char c) {
+        write(c);
+        return this;
+    }
+    
+    public String toString() {
+        return buf.toString();
+    }
+    
+    public StringBuilder getBuffer() {
+        return buf;
+    }
+    
+    public void flush() {
+    	
+    }
+    
+    static int MAX_SIZE = 1024 * 128;
+    
+    /**
+     * 由 StringWriter.close() 改造而来，原先该方法中无任何代码 ，改造如下：
+     * 1：去掉 throws IOException
+     * 2：添加 buf 空间释放处理逻辑
+     * 3：添加 buf.setLength(0)，以便于配合 ThreadLocal 回收利用
+     */
+    public void close() {
+    	if (buf.length() > MAX_SIZE) {
+    		buf = new StringBuilder();	// 释放空间占用过大的 buf
+		} else {
+			buf.setLength(0);
+		}
+    }
+}
+
+
+
+
+