com.alibaba.fastjson.util.IOUtils#stringSize ( )源码实例Demo

public void writeInt(int i) {
    if (i == Integer.MIN_VALUE) {
        write("-2147483648");
        return;
    }

    int size = (i < 0) ? IOUtils.stringSize(-i) + 1 : IOUtils.stringSize(i);

    int newcount = count + size;
    if (newcount > buf.length) {
        if (writer == null) {
            expandCapacity(newcount);
        } else {
            char[] chars = new char[size];
            IOUtils.getChars(i, size, chars);
            write(chars, 0, chars.length);
            return;
        }
    }

    IOUtils.getChars(i, newcount, buf);

    count = newcount;
}
 

public void writeFieldValue(char seperator, String name, int value) {
    if (value == Integer.MIN_VALUE || !quoteFieldNames) {
        write(seperator);
        writeFieldName(name);
        writeInt(value);
        return;
    }

    int intSize = (value < 0) ? IOUtils.stringSize(-value) + 1 : IOUtils.stringSize(value);

    int nameLen = name.length();
    int newcount = count + nameLen + 4 + intSize;
    if (newcount > buf.length) {
        if (writer != null) {
            write(seperator);
            writeFieldName(name);
            writeInt(value);
            return;
        }
        expandCapacity(newcount);
    }

    int start = count;
    count = newcount;

    buf[start] = seperator;

    int nameEnd = start + nameLen + 1;

    buf[start + 1] = keySeperator;

    name.getChars(0, nameLen, buf, start + 2);

    buf[nameEnd + 1] = keySeperator;
    buf[nameEnd + 2] = ':';

    IOUtils.getChars(value, count, buf);
}
 

public void writeFieldValue(char seperator, String name, long value) {
    if (value == Long.MIN_VALUE || !quoteFieldNames) {
        write(seperator);
        writeFieldName(name);
        writeLong(value);
        return;
    }

    int intSize = (value < 0) ? IOUtils.stringSize(-value) + 1 : IOUtils.stringSize(value);

    int nameLen = name.length();
    int newcount = count + nameLen + 4 + intSize;
    if (newcount > buf.length) {
        if (writer != null) {
            write(seperator);
            writeFieldName(name);
            writeLong(value);
            return;
        }
        expandCapacity(newcount);
    }

    int start = count;
    count = newcount;

    buf[start] = seperator;

    int nameEnd = start + nameLen + 1;

    buf[start + 1] = keySeperator;

    name.getChars(0, nameLen, buf, start + 2);

    buf[nameEnd + 1] = keySeperator;
    buf[nameEnd + 2] = ':';

    IOUtils.getChars(value, count, buf);
}
 

public void writeLong(long i) {
    boolean needQuotationMark = isEnabled(SerializerFeature.BrowserCompatible) //
                                && (!isEnabled(SerializerFeature.WriteClassName)) //
                                && (i > 9007199254740991L || i < -9007199254740991L);

    if (i == Long.MIN_VALUE) {
        if (needQuotationMark) write("\"-9223372036854775808\"");
        else write("-9223372036854775808");
        return;
    }

    int size = (i < 0) ? IOUtils.stringSize(-i) + 1 : IOUtils.stringSize(i);

    int newcount = count + size;
    if (needQuotationMark) newcount += 2;
    if (newcount > buf.length) {
        if (writer == null) {
            expandCapacity(newcount);
        } else {
            char[] chars = new char[size];
            IOUtils.getChars(i, size, chars);
            if (needQuotationMark) {
                write('"');
                write(chars, 0, chars.length);
                write('"');
            } else {
                write(chars, 0, chars.length);
            }
            return;
        }
    }

    if (needQuotationMark) {
        buf[count] = '"';
        IOUtils.getChars(i, newcount - 1, buf);
        buf[newcount - 1] = '"';
    } else {
        IOUtils.getChars(i, newcount, buf);
    }

    count = newcount;
}