优化部分代码实现细节

qopo123 · Mar 10, 2016 · 4e96484 · 4e96484
1 parent 6226d9b
commit 4e96484
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Showing 6 changed files with 27 additions and 28 deletions.
diff --git a/src/main/java/com/alibaba/fastjson/JSON.java b/src/main/java/com/alibaba/fastjson/JSON.java
@@ -95,6 +95,9 @@ public abstract class JSON implements JSONStreamAware, JSONAware {
         // com.alibaba.fastjson.serializer.SerializerFeature.WriteSlashAsSpecial.getMask();
         DEFAULT_GENERATE_FEATURE = features;
     }
+
+    /** 长度为 0 的 SerializeFilter 数组  */
+    public static final SerializeFilter[] EMPTY_SERIALIZE_FILTERS = new SerializeFilter[0];
 
     public static Object parse(String text) {
         return parse(text, DEFAULT_PARSER_FEATURE);
@@ -379,7 +382,7 @@ public static List<Object> parseArray(String text, Type[] types) {
 
     // ======================
     public static String toJSONString(Object object) {
-        return toJSONString(object, new SerializerFeature[0]);
+        return toJSONString(object, EMPTY_SERIALIZE_FILTERS);
     }
 
     public static String toJSONString(Object object, SerializerFeature... features) {

diff --git a/src/main/java/com/alibaba/fastjson/JSONObject.java b/src/main/java/com/alibaba/fastjson/JSONObject.java
@@ -167,7 +167,7 @@ public byte getByteValue(String key) {
             return 0;
         }
 
-        return castToByte(value).byteValue();
+        return castToByte(value).byteValue(); // TODO 如果 value 是""、"null"或"NULL"，可能会存在报空指针的情况，是否需要加以处理？ 其他转换也存在类似情况
     }
 
     public Short getShort(String key) {

diff --git a/src/main/java/com/alibaba/fastjson/JSONPath.java b/src/main/java/com/alibaba/fastjson/JSONPath.java
@@ -826,7 +826,7 @@ String readName() {
                 throw new JSONPathException("illeal jsonpath syntax. " + path);
             }
 
-            StringBuffer buf = new StringBuffer();
+            StringBuilder buf = new StringBuilder();
             while (!isEOF()) {
                 if (ch == '\\') {
                     next();

diff --git a/src/main/java/com/alibaba/fastjson/parser/deserializer/JavaBeanDeserializer.java b/src/main/java/com/alibaba/fastjson/parser/deserializer/JavaBeanDeserializer.java
@@ -219,7 +219,7 @@ public <T> T deserialze(DefaultJSONParser parser, Type type, Object fieldName, O
             }
 
             if (lexer.token() != JSONToken.LBRACE && lexer.token() != JSONToken.COMMA) {
-                StringBuffer buf = (new StringBuffer()) //
+                StringBuilder buf = new StringBuilder(72) // 单线程换StringBuilder，并设置初始化容量，避免内部逐步扩容开销
                 .append("syntax error, expect {, actual ") //
                 .append(lexer.tokenName()) //
                 .append(", pos ") //

diff --git a/src/main/java/com/alibaba/fastjson/util/ASMUtils.java b/src/main/java/com/alibaba/fastjson/util/ASMUtils.java
@@ -33,13 +33,13 @@ public static boolean isAndroid() {
     }
 
     public static String getDesc(Method method) {
-        StringBuffer buf = new StringBuffer();
-        buf.append("(");
-        java.lang.Class<?>[] types = method.getParameterTypes();
+    	java.lang.Class<?>[] types = method.getParameterTypes();
+        StringBuilder buf = new StringBuilder((types.length + 1) << 4);
+        buf.append('(');
         for (int i = 0; i < types.length; ++i) {
             buf.append(getDesc(types[i]));
         }
-        buf.append(")");
+        buf.append(')');
         buf.append(getDesc(method.getReturnType()));
         return buf.toString();
     }
@@ -60,7 +60,7 @@ public static String getType(Class<?> parameterType) {
         } else {
             if (!parameterType.isPrimitive()) {
                 String clsName = parameterType.getName();
-                return clsName.replaceAll("\\.", "/");
+                return clsName.replace('.', '/'); // 直接基于字符串替换，不使用正则替换
             } else {
                 return getPrimitiveLetter(parameterType);
             }

diff --git a/src/main/java/com/alibaba/fastjson/util/TypeUtils.java b/src/main/java/com/alibaba/fastjson/util/TypeUtils.java
@@ -140,13 +140,13 @@ public static Character castToChar(Object value) {
             }
 
             if (strVal.length() != 1) {
-                throw new JSONException("can not cast to byte, value : " + value);
+                throw new JSONException("can not cast to char, value : " + value);
             }
 
             return strVal.charAt(0);
         }
 
-        throw new JSONException("can not cast to byte, value : " + value);
+        throw new JSONException("can not cast to char, value : " + value);
     }
 
     public static Short castToShort(Object value) {
@@ -271,15 +271,15 @@ public static Date castToDate(Object value) {
         if (value == null) {
             return null;
         }
+
+        if (value instanceof Date) { // 使用频率最高的，应优先处理
+        	return (Date) value;
+        }
 
         if (value instanceof Calendar) {
             return ((Calendar) value).getTime();
         }
 
-        if (value instanceof Date) {
-            return (Date) value;
-        }
-
         long longValue = -1;
 
         if (value instanceof Number) {
@@ -369,17 +369,17 @@ public static java.sql.Date castToSqlDate(Object value) {
         if (value == null) {
             return null;
         }
-
-        if (value instanceof Calendar) {
-            return new java.sql.Date(((Calendar) value).getTimeInMillis());
-        }
-
+
         if (value instanceof java.sql.Date) {
-            return (java.sql.Date) value;
+        	return (java.sql.Date) value;
         }
-
+        
         if (value instanceof java.util.Date) {
-            return new java.sql.Date(((java.util.Date) value).getTime());
+        	return new java.sql.Date(((java.util.Date) value).getTime());
+        }
+
+        if (value instanceof Calendar) {
+            return new java.sql.Date(((Calendar) value).getTimeInMillis());
         }
 
         long longValue = 0;
@@ -398,7 +398,7 @@ public static java.sql.Date castToSqlDate(Object value) {
         }
 
         if (longValue <= 0) {
-            throw new JSONException("can not cast to Date, value : " + value);
+            throw new JSONException("can not cast to Date, value : " + value); // TODO 忽略 1970-01-01 之前的时间处理？
         }
 
         return new java.sql.Date(longValue);
@@ -503,10 +503,6 @@ public static Integer castToInt(Object value) {
                 return null;
             }
 
-            if ("null".equals(strVal)) {
-                return null;
-            }
-
             if ("null".equals(strVal) || "NULL".equals(strVal)) {
                 return null;
             }