23 10: invokespecial #22; //Method java/lang/String."<init>":(Ljava/lang/String;)V --- 初始化String("1")对象 24 13: invokestatic #25; //Method java/lang/String.valueOf:(Ljava/lang/Object;)Ljava/lang/String; 25 16: invokespecial #29; //Method java/lang/StringBuilder."<init>":(...
initially empty, is maintained privately by the * class {@code String}. * * When the intern method is invoked, if the pool already contains a * string equal to this {@code String} object as determined by * the {@link #equals(Object)} method...
if (java_lang_String::equals(l->literal(), name, len)) { return l->literal(); } } } return NULL; } 它的大体实现结构就是: JAVA 使用 jni 调用c++实现的StringTable的intern方法, StringTable的intern方法跟Java中的HashMap的实现是差不多的, 只是不能自动扩容。默认大小是1009。 要注意的是,Str...
string);jchar*chars=java_lang_String::as_unicode_string(string,length,CHECK_NULL);oop result=intern(h_string,chars,length,CHECK_NULL);returnresult;}...oop StringTable::intern(Handle string_or_null_h,jchar*name,int len,TRAPS){...unsigned int hash=java_lang_String::hash_code(...
1.Java代码# /*** Returns a canonical representation for the string object. * * A pool of strings, initially empty, is maintained privately by the * class {@codeString}. * * When the intern method is invoked, if the pool already contains a * string ...
java源码 /*** Returns a canonical representation for the string object. * * A pool of strings, initially empty, is maintained privately by the * class String. * * When the intern method is invoked, if the pool already contains a * string equal to this ...
java7 的String.intern() java7中,String.intern()方法做了重要的改变。 首先,字符串池的存储位置从永久带(java8中,方法区(Method area)取代了永久带(PermGen)) 挪到了堆。这样带来了两个重要的影响 1. 字符串常量池中的对象可以被GC 2. 字符串常量池的大小不再受永久带内存大小限制(在jdk6中,永久带的大...
1,JAVA 代码 /** * Returns a canonical representation for the string object. ** A pool of strings, initially empty, is maintained privately by the * classString. ** When the intern method is invoked, if the pool already contains a * string equal to thisString...
两个new String相加会被优化为StringBuilder，可以通过javac和javap查看汇编指令如下：javac InternTest.javajavap -c InternTest publicclasscom.justin.java.lang.InternTest{ publiccom.justin.java.lang.InternTest();Code:: aload_0 1: invokespecial #1// Method java/lang/Object."<init>":()V4:return...
简单来说,在Java8中,String类维护了一个字符串常量池(注意此常量池在运行期间位于堆中),当调用intern方法时,首先在常量池中查看是否已有相同的字符串(字符串是否相同使用String的equal方法判断),如果常量池中已有,则直接返回该字符串的引用,如果没有,则将当前字符串对象加入常量池中,并返回当前字符串的引用。