本篇内容介绍了“RedisOutputStream.java的源码是什么”的有关知识，在实际案例的操作过程中，不少人都会遇到这样的困境，接下来就让小编带领大家学习一下如何处理这些情况吧！希望大家仔细阅读，能够学有所成！
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package redis.clients.util;
import java.io.*;
import java.nio.charset.Charset;
/**
* The class implements a buffered output stream without synchronization
* There are also special operations like in-place string encoding.
* This stream fully ignore mark/reset and should not be used outside Jedis
*/
public final class RedisOutputStream extends FilterOutputStream {
protected final byte buf[];//缓冲区
protected int count;//计数器
public static final Charset CHARSET = Charset.forName("UTF-8");//编码方式
public RedisOutputStream(OutputStream out) {//初始化
this(out, 8192);
}
public RedisOutputStream(OutputStream out, int size) {//初始化
super(out);
if (size <= 0) {
throw new IllegalArgumentException("Buffer size <= 0");
}
buf = new byte[size];
}
private void flushBuffer() throws IOException {//将所有字符都写出去
if (count > 0) {
out.write(buf, 0, count);
count = 0;
}
}
public void write(int b) throws IOException {//写到缓冲区，满时执行缓冲区清除
buf[count++] = (byte) b;
if (count == buf.length) {
flushBuffer();
}
}
public void write(byte b[], int off, int len) throws IOException {//写到缓冲区
if (len >= buf.length) {
flushBuffer();
out.write(b, off, len);
} else {
if (len >= buf.length - count) {
flushBuffer();
}
System.arraycopy(b, off, buf, count, len);
count += len;
}
}
public void writeAsciiCrLf(String in) throws IOException {//写到缓冲区
final int size = in.length();
for (int i = 0; i != size; ++i) {
buf[count++] = (byte) in.charAt(i);
if (count == buf.length) {
flushBuffer();
}
}
writeCrLf();
}
public static boolean isSurrogate(char ch) {//XXX
return ch >= Character.MIN_SURROGATE && ch <= Character.MAX_SURROGATE;
}
public static int utf8Length (String str) {//utf8编码的长度
int strLen = str.length(), utfLen = 0;
for(int i = 0; i != strLen; ++i) {
char c = str.charAt(i);
if (c < 0x80) {
utfLen++;
} else if (c < 0x800) {
utfLen += 2;
} else if (isSurrogate(c)) {
i++;
utfLen += 4;
} else {
utfLen += 3;
}
}
return utfLen;
}
public void writeCrLf() throws IOException {//写到缓冲区里
if (2 >= buf.length - count) {
flushBuffer();
}
buf[count++] = '\r';
buf[count++] = '\n';
}
public void writeUtf8CrLf(String str) throws IOException {//XXX
int strLen = str.length();
int i;
for (i = 0; i < strLen; i++) {
char c = str.charAt(i);
if (!(c < 0x80)) break;
buf[count++] = (byte) c;
if(count == buf.length) {
flushBuffer();
}
}
for (; i < strLen; i++) {
char c = str.charAt(i);
if (c < 0x80) {
buf[count++] = (byte) c;
if(count == buf.length) {
flushBuffer();
}
} else if (c < 0x800) {
if(2 < buf.length - count) {
flushBuffer();
}
buf[count++] = (byte)(0xc0 | (c >> 6));
buf[count++] = (byte)(0x80 | (c & 0x3f));
} else if (isSurrogate(c)) {
if(4 < buf.length - count) {
flushBuffer();
}
int uc = Character.toCodePoint(c, str.charAt(i++));
buf[count++] = ((byte)(0xf0 | ((uc >> 18))));
buf[count++] = ((byte)(0x80 | ((uc >> 12) & 0x3f)));
buf[count++] = ((byte)(0x80 | ((uc >> 6) & 0x3f)));
buf[count++] = ((byte)(0x80 | (uc & 0x3f)));
} else {
if(3 < buf.length - count) {
flushBuffer();
}
buf[count++] =((byte)(0xe0 | ((c >> 12))));
buf[count++] =((byte)(0x80 | ((c >> 6) & 0x3f)));
buf[count++] =((byte)(0x80 | (c & 0x3f)));
}
}
writeCrLf();
}
private final static int[] sizeTable = {9, 99, 999, 9999, 99999, 999999, 9999999, 99999999, 999999999, Integer.MAX_VALUE};
private final static byte[] DigitTens = {
'0', '0', '0', '0', '0', '0', '0', '0', '0', '0',
'1', '1', '1', '1', '1', '1', '1', '1', '1', '1',
'2', '2', '2', '2', '2', '2', '2', '2', '2', '2',
'3', '3', '3', '3', '3', '3', '3', '3', '3', '3',
'4', '4', '4', '4', '4', '4', '4', '4', '4', '4',
'5', '5', '5', '5', '5', '5', '5', '5', '5', '5',
'6', '6', '6', '6', '6', '6', '6', '6', '6', '6',
'7', '7', '7', '7', '7', '7', '7', '7', '7', '7',
'8', '8', '8', '8', '8', '8', '8', '8', '8', '8',
'9', '9', '9', '9', '9', '9', '9', '9', '9', '9',
};
private final static byte[] DigitOnes = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
};
private final static byte[] digits = {
'0', '1', '2', '3', '4', '5',
'6', '7', '8', '9', 'a', 'b',
'c', 'd', 'e', 'f', 'g', 'h',
'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't',
'u', 'v', 'w', 'x', 'y', 'z'
};
public void writeIntCrLf(int value) throws IOException {//写一个整数
if (value < 0) {
write('-');
value = -value;
}
int size = 0;
while (value > sizeTable[size])
size++;
size++;
if (size >= buf.length - count) {
flushBuffer();
}
int q, r;
int charPos = count + size;
while (value >= 65536) {
q = value / 100;
r = value - ((q << 6) + (q << 5) + (q << 2));
value = q;
buf[--charPos] = DigitOnes[r];
buf[--charPos] = DigitTens[r];
}
for (; ;) {
q = (value * 52429) >>> (16 + 3);
r = value - ((q << 3) + (q << 1));
buf[--charPos] = digits[r];
value = q;
if (value == 0) break;
}
count += size;
writeCrLf();
}
public void flush() throws IOException {//写完缓冲区，并且对out执行flush操作。
flushBuffer();
out.flush();
}
}“RedisOutputStream.java的源码是什么”的内容就介绍到这里了，感谢大家的阅读。如果想了解更多行业相关的知识可以关注亿速云网站，小编将为大家输出更多高质量的实用文章！
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原文链接：https://my.oschina.net/qiangzigege/blog/207761
