问题：
使用XStream去将对象转为想xml的时候，对象中的一个url字段值具有特殊字符
例如：lsid=B5D453EFABD00D0A878756E0D0B845B9&uiid=B74D04E5EF789344B6392D04161A5144&
经过XStream的toXml方法进行输出的时候，会被转义成如下：
lsid=B5D453EFABD00D0A878756E0D0B845B9&uiid=B74D04E5EF789344B6392D04161A5144&
它将&特殊字符转义成了&，这样可不行，通过webservice接口拿到数据无法直接使用该url了。
解决办法：
1.定义编写器，它将XML输出到打印良好的缩进流中。
/**
* <p>主要重写特殊字符不转义，源码参考 {@link com.thoughtworks.xstream.io.xml.PrettyPrintWriter}</p>
* <p>重写的方法：{@link #writeText(String, boolean)}</p>
*/
public class NoneEscapePrettyPintWriter extends AbstractWriter {
public static int XML_QUIRKS = -1;
public static int XML_1_0 = 0;
public static int XML_1_1 = 1;
private final QuickWriter writer;
private final FastStack elementStack = new FastStack(16);
private final char[] lineIndenter;
private final int mode;
private boolean tagInProgress;
protected int depth;
private boolean readyForNewLine;
private boolean tagIsEmpty;
private String newLine;
private static final char[] NULL = "�".toCharArray();
private static final char[] AMP = "&".toCharArray();
private static final char[] LT = "<".toCharArray();
private static final char[] GT = ">".toCharArray();
private static final char[] CR = "
".toCharArray();
private static final char[] QUOT = """.toCharArray();
private static final char[] APOS = "'".toCharArray();
private static final char[] CLOSE = "</".toCharArray();
private NoneEscapePrettyPintWriter(
Writer writer, int mode, char[] lineIndenter, NameCoder nameCoder,
String newLine) {
super(nameCoder);
this.writer = new QuickWriter(writer);
this.lineIndenter = lineIndenter;
this.newLine = newLine;
this.mode = mode;
if (mode < XML_QUIRKS || mode > XML_1_1) {
throw new IllegalArgumentException("Not a valid XML mode");
}
}
/**
* @since 1.4
*/
public NoneEscapePrettyPintWriter(Writer writer, NameCoder nameCoder) {
this(writer, XML_QUIRKS, new char[]{' ', ' '}, nameCoder, "\n");
}
public void startNode(String name) {
String escapedName = encodeNode(name);
tagIsEmpty = false;
finishTag();
writer.write('<');
writer.write(escapedName);
elementStack.push(escapedName);
tagInProgress = true;
depth++;
readyForNewLine = true;
tagIsEmpty = true;
}
public void startNode(String name, Class clazz) {
startNode(name);
}
public void setValue(String text) {
readyForNewLine = false;
tagIsEmpty = false;
finishTag();
writeText(writer, text);
}
public void addAttribute(String key, String value) {
writer.write(' ');
writer.write(encodeAttribute(key));
writer.write('=');
writer.write('\"');
writeAttributeValue(writer, value);
writer.write('\"');
}
protected void writeAttributeValue(QuickWriter writer, String text) {
writeText(text, true);
}
protected void writeText(QuickWriter writer, String text) {
writeText(text, false);
}
private void writeText(String text, boolean isAttribute) {
int length = text.length();
for (int i = 0; i < length; i++) {
char c = text.charAt(i);
switch (c) {
case '\0':
if (mode == XML_QUIRKS) {
this.writer.write(NULL);
} else {
throw new StreamException("Invalid character 0x0 in XML stream");
}
break;
case '&':
if (isAttribute)
this.writer.write(AMP);
else
this.writer.write(c);
break;
case '<':
if (isAttribute)
this.writer.write(LT);
else
this.writer.write(c);
break;
case '>':
if (isAttribute)
this.writer.write(GT);
else
this.writer.write(c);
break;
case '"':
if (isAttribute)
this.writer.write(QUOT);
else
this.writer.write(c);
break;
case '\'':
if (isAttribute)
this.writer.write(APOS);
else
this.writer.write(c);
break;
case '\r':
if (isAttribute)
this.writer.write(CR);
else
this.writer.write(c);
break;
case '\t':
case '\n':
if (!isAttribute) {
this.writer.write(c);
break;
}
default:
if (Character.isDefined(c) && !Character.isISOControl(c)) {
if (mode != XML_QUIRKS) {
if (c > '\ud7ff' && c < '\ue000') {
throw new StreamException("Invalid character 0x"
+ Integer.toHexString(c)
+ " in XML stream");
}
}
this.writer.write(c);
} else {
if (mode == XML_1_0) {
if (c < 9
|| c == '\u000b'
|| c == '\u000c'
|| c == '\u000e'
|| (c >= '\u000f' && c <= '\u001f')) {
throw new StreamException("Invalid character 0x"
+ Integer.toHexString(c)
+ " in XML 1.0 stream");
}
}
if (mode != XML_QUIRKS) {
if (c == '\ufffe' || c == '\uffff') {
throw new StreamException("Invalid character 0x"
+ Integer.toHexString(c)
+ " in XML stream");
}
}
this.writer.write("&#x");
this.writer.write(Integer.toHexString(c));
this.writer.write(';');
}
}
}
}
public void endNode() {
depth--;
if (tagIsEmpty) {
writer.write('/');
readyForNewLine = false;
finishTag();
elementStack.popSilently();
} else {
finishTag();
writer.write(CLOSE);
writer.write((String) elementStack.pop());
writer.write('>');
}
readyForNewLine = true;
if (depth == 0) {
writer.flush();
}
}
private void finishTag() {
if (tagInProgress) {
writer.write('>');
}
tagInProgress = false;
if (readyForNewLine) {
endOfLine();
}
readyForNewLine = false;
tagIsEmpty = false;
}
protected void endOfLine() {
writer.write(getNewLine());
for (int i = 0; i < depth; i++) {
writer.write(lineIndenter);
}
}
public void flush() {
writer.flush();
}
public void close() {
writer.close();
}
/**
* Retrieve the line terminator.
* <p>
* This method returns always a line feed, since according the XML specification any parser
* must ignore a carriage return. Overload this method, if you need different behavior.
*
* @return the line terminator
* @since 1.3
*/
protected String getNewLine() {
return newLine;
}
}
2.重写 XppDriver 解析器的HierarchicalStreamWriter方法
/**
* 重写 XppDriver
*/
public class NoneEscapeAppDriver extends XppDriver {
@Override
public HierarchicalStreamWriter createWriter(Writer out) {
return new NoneEscapePrettyPintWriter(out, getNameCoder());
}
}
3.使用：
XStream xStream = new XStream(new NoneEscapeAppDriver());
xStream.processAnnotations(resultData.getClass());
String xmlHead = "<?xml version=\"1.0\" encoding=\"gb2312\"?>";
return xmlHead + xStream.toXML(resultData);再次输出的时候对象字段的值就没有乱码了。
原文地址：https://blog.csdn.net/sinat_32364425/article/details/102476954
