com.kaka.util.IOUtils Maven / Gradle / Ivy
package com.kaka.util;
import java.io.*;
import java.util.function.Consumer;
/**
* IO流相关工具集
*
* @author zkpursuit
*/
public class IOUtils {
public static final int bufferSize = 64 * 1024;
/**
* 从输入流中读取字节数据
*
* @param in 输入流
* @param dest 目标字节数组，存储输入流中的字节数据
* @param destPos 存入目标字节数组时的起始位置
* @param length 从输入流中读取字节的数量
* @return 字节数组
* @throws IOException 数据流访问异常
*/
public static int readBytes(InputStream in, byte[] dest, int destPos, int length) throws IOException {
if (in == null) {
return -1;
}
if (length == 0) {
return -1;
}
int c = in.read();
if (c == -1) {
return -1;
}
dest[destPos] = (byte) c;
int i = 1;
try {
for (; i < length; i++) {
c = in.read();
if (c == -1) {
break;
}
dest[destPos + i] = (byte) c;
}
} catch (IOException ee) {
}
return i;
}
/**
* 从输入流中读取字节数据
*
* @param in 输入流
* @return 字节数组
* @throws IOException 数据流访问异常
*/
public static byte[] readBytes(final InputStream in) throws IOException {
return readBytes(in, bufferSize);
}
/**
* 从输入流中读取字节数据
*
* @param input 输入流
* @param size 预估大小
* @return 字节数组
* @throws IOException 数据流访问异常
*/
public static byte[] readBytes(final InputStream input, final int size) throws IOException {
if (size < 0) {
throw new IllegalArgumentException("Size must be equal or greater than zero: " + size);
}
if (size == 0) {
return new byte[0];
}
byte[] bytes = new byte[size];
int count = readBytes(input, bytes, 0, size);
if (size > count) {
byte[] newBytes = new byte[count];
System.arraycopy(bytes, 0, newBytes, 0, count);
return newBytes;
}
return bytes;
}
/**
* 将InputStream输入流转换为字符串
*
* @param is 输入流
* @param charset 字符编码
* @return 字符串
* @throws IOException 数据流访问异常
*/
public static String toString(InputStream is, String charset) throws IOException {
byte[] bytes = readBytes(is);
return new String(bytes, 0, bytes.length, charset);
}
/**
* 将InputStream输入流转换为字符串
*
* @param is 输入字节流
* @param charset 字符编码
* @return 将输入字节流转换为字符串
* @throws IOException 数据流访问异常
*/
public static String toString(InputStream is, java.nio.charset.Charset charset) throws IOException {
byte[] bytes = readBytes(is);
return new String(bytes, 0, bytes.length, charset);
}
/**
* 转换输入字节流为字符流
*
* @param is 输入字节流
* @param charset 字符编码
* @return 输入字符流
* @throws UnsupportedEncodingException 编码错误
*/
public static BufferedReader toBufferedReader(InputStream is, final String charset) throws UnsupportedEncodingException {
return new BufferedReader(new InputStreamReader(is, charset));
}
/**
* 转换输入字节流为字符流
*
* @param is 输入字节流
* @param charset 字符编码
* @return 输入字符流
* @throws UnsupportedEncodingException 编码错误
*/
public static BufferedReader toBufferedReader(InputStream is, final java.nio.charset.Charset charset) throws UnsupportedEncodingException {
return new BufferedReader(new InputStreamReader(is, charset));
}
/**
* 读取数据中的行
*
* @param reader 输入字符流
* @param action 字符串行数据访问器
* @throws IOException 数据流访问异常
*/
public static void readLines(final BufferedReader reader, Consumer action) throws IOException {
String line = reader.readLine();
while (line != null) {
action.accept(line);
line = reader.readLine();
}
}
}