Java Deflater needsInput()函数及示例

java.util.zip中 Deflater类 的 needsInput() 函数用于检查输入数据缓冲区是否为空。如果输入数据缓冲区是空的，则调用 setInput() 函数来提供输入数据。

函数签名

public boolean needsInput()

语法

d.needsInput();

参数： 该函数不需要参数

返回类型： 该函数返回一个布尔值，即如果输入缓冲区为空，则返回真，否则返回假。

异常： 该函数不抛出任何异常。

例子 1 :

// Java program to describe the use
// of needsInput() function
  
import java.util.zip.*;
import java.io.UnsupportedEncodingException;
  
class GFG {
    public static void main(String args[])
        throws UnsupportedEncodingException
    {
        // deflater
        Deflater d = new Deflater();
  
        // get the text
        String pattern = "GeeksforGeeks", text = "";
  
        // generate the text
        for (int i = 0; i < 4; i++)
            text += pattern;
  
        // set the Input for deflator
        d.setInput(text.getBytes("UTF-8"));
  
        // finish
        d.finish();
  
        // output bytes
        byte output[] = new byte[1024];
  
        // does the deflater need input
        System.out.println("Input Buffer Empty ? :"
                           + d.needsInput());
  
        // compress the data
        int size = d.deflate(output);
  
        // compressed String
        System.out.println("Compressed String :"
                           + new String(output)
                           + "\n Size " + size);
  
        // original String
        System.out.println("Original String :"
                           + text + "\n Size "
                           + text.length());
  
        // does the deflater need input
        System.out.println("Input Buffer Empty ? :"
                           + d.needsInput());
  
        // end
        d.end();
    }
}

输出

Input Buffer Empty ? :false
Compressed String :x?sOM?.N?/r???q??
 Size 21
Original String :GeeksforGeeksGeeksforGeeksGeeksforGeeksGeeksforGeeks
 Size 52
Input Buffer Empty ? :true

参考资料: https://docs.oracle.com/javase/7/docs/api/java/util/zip/Deflater.html#needsInput()