InputStream与DataInputStream区别

DataInputStream类继承了InputStream，同是实现了DataInput接口，也就是说比普通的InputStream多一些方法。 
增加方法如下： 

public abstract void readFully(byte abyte0[]) 
        throws IOException; 

    public abstract void readFully(byte abyte0[], int i, int j) 
        throws IOException; 

    public abstract int skipBytes(int i) 
        throws IOException; 

    public abstract boolean readBoolean() 
        throws IOException; 

    public abstract byte readByte() 
        throws IOException; 

    public abstract int readUnsignedByte() 
        throws IOException; 

    public abstract short readShort() 
        throws IOException; 

    public abstract int readUnsignedShort() 
        throws IOException; 

    public abstract char readChar() 
        throws IOException; 

    public abstract int readInt() 
        throws IOException; 

    public abstract long readLong() 
        throws IOException; 

    public abstract float readFloat() 
        throws IOException; 

    public abstract double readDouble() 
        throws IOException; 

    public abstract String readUTF() 
        throws IOException;