javap –verbose class名 查看class文件的具体内容

javap -c class名

继续看io类

接口 java.io.Closeable

功能：关闭流和相应的资源

java.io.console

功能：使用字节控制台，与当前的java virtual machine 相关

java.io.DataInput

功能：从二进制流中读取字节

java.io.DataInputStream

功能：从一个输入流中读取原始java数据类型。

public class DataInputStream extends FilterInputStream implements DataInput

java.io.DataOutput

功能：任何java原始类型的数据转化为字节，将这些字节写到字节流流中

java.io.DataOutputStream

功能：将原始的java数据类型写入输出流中，也可以用datainputstream将数据读回

java.io.DeleteOnExitHook

功能：持有已经删除的文件集

java.io.EOFException

功能：指示文件的结尾，或已到达流文件的结尾。

java.io.ExpiringCache

功能：清除过期的实体对象

static class Entry {

private long   timestamp;

private String val;

Entry(long timestamp, String val) {

this.timestamp = timestamp;

this.val = val;

}

long   timestamp()                  { return timestamp;           }

void   setTimestamp(long timestamp) { this.timestamp = timestamp; }

String val()                        { return val;                 }

void   setVal(String val)           { this.val = val;             }

}

java.io.Externalizable

功能：只有实现了这个接口的实例才会写入序列化的流中，负责保存这个实例的内容。

java.io.File

功能：代表抽象的文件和目录路径名

By default the classes in the

java.io package always resolve relative pathnames against the

current user directory.  This directory is named by the system property

user.dir, and is typically the directory in which the Java

virtual machine was invoked.

static private FileSystem fs = FileSystem.getFileSystem();

file.separator

On UNIX systems the value of this

field is '/';

on Microsoft Windows systems it is '\\'.

public static final char separatorChar = fs.getSeparator();

This character is used to

separate filenames in a sequence of files given as a path list.

On UNIX systems, this character is ':'; on Microsoft Windows systems it is ';'.

public static final char pathSeparatorChar = fs.getPathSeparator();

public File(URI uri) {

// Check our many preconditions

if (!uri.isAbsolute())

throw new IllegalArgumentException("URI is not absolute");

if (uri.isOpaque())

throw new IllegalArgumentException("URI is not hierarchical");

String scheme = uri.getScheme();

if ((scheme == null) || !scheme.equalsIgnoreCase("file"))

throw new IllegalArgumentException("URI scheme is not \"file\"");

if (uri.getAuthority() != null)

throw new IllegalArgumentException("URI has an authority component");

if (uri.getFragment() != null)

throw new IllegalArgumentException("URI has a fragment component");

if (uri.getQuery() != null)

throw new IllegalArgumentException("URI has a query component");

String p = uri.getPath();

if (p.equals(""))

throw new IllegalArgumentException("URI path component is empty");

// Okay, now initialize

p = fs.fromURIPath(p);

if (File.separatorChar != '/')

p = p.replace('/', File.separatorChar);

this.path = fs.normalize(p);

this.prefixLength = fs.prefixLength(this.path);

}