package com.xiaoleilu.hutool;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.util.Collection;
import com.xiaoleilu.hutool.exceptions.UtilException;
/**
* IO工具类
* @author xiaoleilu
*
*/
public class IoUtil {
/** 默认缓存大小 */
public final static int DEFAULT_BUFFER_SIZE = 1024;
//-------------------------------------------------------------------------------------- Copy start
/**
* 将Reader中的内容复制到Writer中
* 使用默认缓存大小
* @param reader Reader
* @param writer Writer
* @return 拷贝的字节数
* @throws IOException
*/
public static int copy(Reader reader, Writer writer) throws IOException {
return copy(reader, writer, DEFAULT_BUFFER_SIZE);
}
/**
* 将Reader中的内容复制到Writer中
*/
public static int copy(Reader reader, Writer writer, int bufferSize) throws IOException {
char[] buffer = new char[bufferSize];
int count = 0;
int readSize;
while ((readSize = reader.read(buffer, 0, bufferSize)) >= 0) {
writer.write(buffer, 0, readSize);
count += readSize;
}
writer.flush();
return count;
}
/**
* 拷贝流，使用默认Buffer大小
* @param in 输入流
* @param out 输出流
* @throws IOException
*/
public static int copy(InputStream in, OutputStream out) throws IOException {
return copy(in, out, DEFAULT_BUFFER_SIZE);
}
/**
* 拷贝流
* @param in 输入流
* @param out 输出流
* @param bufferSize 缓存大小
* @throws IOException
*/
public static int copy(InputStream in, OutputStream out, int bufferSize) throws IOException {
byte[] buffer = new byte[bufferSize];
int count = 0;
for (int n = -1; (n = in.read(buffer)) != -1;) {
out.write(buffer, 0, n);
count += n;
}
out.flush();
return count;
}
/**
* 拷贝文件流，使用NIO
* @param in 输入
* @param out 输出
* @return 拷贝的字节数
* @throws IOException
*/
public static long copy(FileInputStream in, FileOutputStream out) throws IOException {
FileChannel inChannel = in.getChannel();
FileChannel outChannel = out.getChannel();
return inChannel.transferTo(0, inChannel.size(), outChannel);
}
//-------------------------------------------------------------------------------------- Copy end
/**
* 获得一个文件读取器
* @param in 输入流
* @param charset 字符集
* @return BufferedReader对象
* @throws IOException
*/
public static BufferedReader getReader(InputStream in, String charset) throws IOException{
InputStreamReader reader = null;
if(StrUtil.isBlank(charset)) {
reader = new InputStreamReader(in);
}else {
reader = new InputStreamReader(in, charset);
}
return new BufferedReader(reader);
}
/**
* 从流中读取内容
*
* @param in 输入流
* @param charset 字符集
* @return 内容
* @throws IOException
*/
public static String getString(InputStream in, String charset) throws IOException {
final long len = in.available();
if (len >= Integer.MAX_VALUE) {
throw new IOException("File is larger then max array size");
}
byte[] bytes = new byte[(int) len];
in.read(bytes);
return new String(bytes, charset);
}
/**
* 从流中读取内容
*
* @param in 输入流
* @param charset 字符集
* @param collection 返回集合
* @return 内容
* @throws IOException
*/
public static <T extends Collection<String>> T getLines(InputStream in, String charset, T collection) throws IOException {
// 从返回的内容中读取所需内容
BufferedReader reader = new BufferedReader(new InputStreamReader(in, charset));
String line = null;
while ((line = reader.readLine()) != null) {
collection.add(line);
}
return collection;
}
/**
* 从FileChannel中读取内容
* @param fileChannel 文件管道
* @param charset 字符集
* @return 内容
* @throws IOException
*/
public static String getString(FileChannel fileChannel, String charset) throws IOException {
final MappedByteBuffer buffer = fileChannel.map(FileChannel.MapMode.READ_ONLY, 0, fileChannel.size()).load();
return CharsetUtil.str(buffer, charset);
}
/**
* String 转为 流
* @param content 内容
* @param charset 编码
* @return 字节流
*/
public static ByteArrayInputStream toStream(String content, String charset) {
if(content == null) {
return null;
}
byte[] data = null;
try {
data = StrUtil.isBlank(charset) ? content.getBytes() : content.getBytes(charset);
} catch (UnsupportedEncodingException e) {
throw new UtilException(StrUtil.format("Invalid charset [{}] !", charset), e);
}
return new ByteArrayInputStream(data);
}
/**
* 将多部分内容写到流中，自动转换为字符串
* @param out 输出流
* @param charset 写出的内容的字符集
* @param isCloseOut 写入完毕是否关闭输出流
* @param contents 写入的内容，调用toString()方法，不包括不会自动换行
* @throws IOException
*/
public static void write(OutputStream out, String charset, boolean isCloseOut, Object... contents) throws IOException {
OutputStreamWriter osw = null;
try {
osw = new OutputStreamWriter(out, charset);
for (Object content : contents) {
if(content != null) {
osw.write(content.toString());
}
}
} catch (Exception e) {
throw new IOException("Write content to OutputStream error!", e);
}finally {
if(isCloseOut) {
FileUtil.close(osw);
}
}
}
/**
* 打印内容，调用系统的System.out.println方法
* @param content 内容，会调用toString方法， 当内容中有 {} 表示变量占位符
* @param param 参数
*/
public static void echo(Object content, Object... param) {
if(content == null) {
System.out.println(content);
}
System.out.println(StrUtil.format(content.toString(), param));
}
}