在使用XmlSerializer过程中遇到了下面这个错误
java.lang.IllegalArgumentException: Illegal character (d83d) at org.kxml2.io.KXmlSerializer.reportInvalidCharacter(KXmlSerializer.java:144) at org.kxml2.io.KXmlSerializer.writeEscaped(KXmlSerializer.java:130) at org.kxml2.io.KXmlSerializer.attribute(KXmlSerializer.java:465)
这是安卓4.4及以下系统的bug，XmlSerializer类不支持emoji表情，google在android4.4以上已经修复了这个问题
崩溃的具体原因目前不是很清楚，网上说是XmlSerializer忽略utf-16编码情况，具体也不是很了解，等后续再来研究一下。
支持4.4以下解决方案如下
将XmlSerializer serializer = Xml.newSerializer();
替换成XmlSerializer serializer = new KXmlSerializer();
import java.io.*;
import java.util.Locale;
import org.xmlpull.v1.*;
/**
* source:https://github.com/cgeo/cgeo/issues/2635
* 解决XmlSerializer在android4.4及以下不支持emoji的bug
*/
public class KXmlSerializer implements XmlSerializer {
private static final int BUFFER_LEN = 8192;
private final char[] mText = new char[BUFFER_LEN];
private int mPos;
// static final String UNDEFINED = ":";
private Writer writer;
private boolean pending;
private int auto;
private int depth;
private String[] elementStack = new String[12];
//nsp/prefix/name
private int[] nspCounts = new int[4];
private String[] nspStack = new String[8];
//prefix/nsp; both empty are ""
private boolean[] indent = new boolean[4];
private boolean unicode;
private String encoding;
private void append(char c) throws IOException {
if (mPos >= BUFFER_LEN) {
flushBuffer();
}
mText[mPos++] = c;
}
private void append(String str, int i, int length) throws IOException {
while (length > 0) {
if (mPos == BUFFER_LEN) {
flushBuffer();
}
int batch = BUFFER_LEN - mPos;
if (batch > length) {
batch = length;
}
str.getChars(i, i + batch, mText, mPos);
i += batch;
length -= batch;
mPos += batch;
}
}
private void append(String str) throws IOException {
append(str, 0, str.length());
}
private final void flushBuffer() throws IOException {
if(mPos > 0) {
writer.write(mText, 0, mPos);
writer.flush();
mPos = 0;
}
}
private final void check(boolean close) throws IOException {
if (!pending)
return;
depth++;
pending = false;
if (indent.length <= depth) {
boolean[] hlp = new boolean[depth + 4];
System.arraycopy(indent, 0, hlp, 0, depth);
indent = hlp;
}
indent[depth] = indent[depth - 1];
for (int i = nspCounts[depth - 1]; i < nspCounts[depth]; i++) {
append(" xmlns");
if (!nspStack[i * 2].isEmpty()) {
append(':');
append(nspStack[i * 2]);
}
else if (getNamespace().isEmpty() && !nspStack[i * 2 + 1].isEmpty())
throw new IllegalStateException("Cannot set default namespace for elements in no namespace");
append("=\"");
writeEscaped(nspStack[i * 2 + 1], '"');
append('"');
}
if (nspCounts.length <= depth + 1) {
int[] hlp = new int[depth + 8];
System.arraycopy(nspCounts, 0, hlp, 0, depth + 1);
nspCounts = hlp;
}
nspCounts[depth + 1] = nspCounts[depth];
// nspCounts[depth + 2] = nspCounts[depth];
if (close) {
append(" />");
} else {
append('>');
}
}
private final void writeEscaped(String s, int quot) throws IOException {
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
switch (c) {
case '\n':
case '\r':
case '\t':
if(quot == -1)
append(c);
else
append("&#"+((int) c)+';');
break;
case '&' :
append("&");
break;
case '>' :
append(">");
break;
case '<' :
append("<");
break;
default:
if (c == quot) {
append(c == '"' ? """ : "'");
break;
}
// BEGIN android-changed: refuse to output invalid characters
// See http://www.w3.org/TR/REC-xml/#charsets for definition.
// No other Java XML writer we know of does this, but no Java
// XML reader we know of is able to parse the bad output we'd
// otherwise generate.
// Note: tab, newline, and carriage return have already been
// handled above.
boolean allowedInXml = (c >= 0x20 && c <= 0xd7ff) || (c >= 0xe000 && c <= 0xfffd);
if (allowedInXml) {
if (unicode || c < 127) {
append(c);
} else {
append("&#" + ((int) c) + ";");
}
} else if (Character.isHighSurrogate(c) && i < s.length() - 1) {
writeSurrogate(c, s.charAt(i + 1));
++i;
} else {
reportInvalidCharacter(c);
}
// END android-changed
}
}
}
// BEGIN android-added
private static void reportInvalidCharacter(char ch) {
throw new IllegalArgumentException("Illegal character (U+" + Integer.toHexString((int) ch) + ")");
}
// END android-added
/*
private final void writeIndent() throws IOException {
writer.write("\r\n");
for (int i = 0; i < depth; i++)
writer.write(' ');
}*/
public void docdecl(String dd) throws IOException {
append("<!DOCTYPE");
append(dd);
append('>');
}
public void endDocument() throws IOException {
while (depth > 0) {
endTag(elementStack[depth * 3 - 3], elementStack[depth * 3 - 1]);
}
flush();
}
public void entityRef(String name) throws IOException {
check(false);
append('&');
append(name);
append(';');
}
public boolean getFeature(String name) {
//return false;
return (
"http://xmlpull.org/v1/doc/features.html#indent-output"
.equals(
name))
? indent[depth]
: false;
}
public String getPrefix(String namespace, boolean create) {
try {
return getPrefix(namespace, false, create);
}
catch (IOException e) {
throw new RuntimeException(e.toString());
}
}
private final String getPrefix(
String namespace,
boolean includeDefault,
boolean create)
throws IOException {
for (int i = nspCounts[depth + 1] * 2 - 2;
i >= 0;
i -= 2) {
if (nspStack[i + 1].equals(namespace)
&& (includeDefault || !nspStack[i].isEmpty())) {
String cand = nspStack[i];
for (int j = i + 2;
j < nspCounts[depth + 1] * 2;
j++) {
if (nspStack[j].equals(cand)) {
cand = null;
break;
}
}
if (cand != null)
return cand;
}
}
if (!create)
return null;
String prefix;
if (namespace.isEmpty())
prefix = "";
else {
do {
prefix = "n" + (auto++);
for (int i = nspCounts[depth + 1] * 2 - 2;
i >= 0;
i -= 2) {
if (prefix.equals(nspStack[i])) {
prefix = null;
break;
}
}
}
while (prefix == null);
}
boolean p = pending;
pending = false;
setPrefix(prefix, namespace);
pending = p;
return prefix;
}
public Object getProperty(String name) {
throw new RuntimeException("Unsupported property");
}
public void ignorableWhitespace(String s)
throws IOException {
text(s);
}
public void setFeature(String name, boolean value) {
if ("http://xmlpull.org/v1/doc/features.html#indent-output"
.equals(name)) {
indent[depth] = value;
}
else
throw new RuntimeException("Unsupported Feature");
}
public void setProperty(String name, Object value) {
throw new RuntimeException(
"Unsupported Property:" + value);
}
public void setPrefix(String prefix, String namespace)
throws IOException {
check(false);
if (prefix == null)
prefix = "";
if (namespace == null)
namespace = "";
String defined = getPrefix(namespace, true, false);
// boil out if already defined
if (prefix.equals(defined))
return;
int pos = (nspCounts[depth + 1]++) << 1;
if (nspStack.length < pos + 1) {
String[] hlp = new String[nspStack.length + 16];
System.arraycopy(nspStack, 0, hlp, 0, pos);
nspStack = hlp;
}
nspStack[pos++] = prefix;
nspStack[pos] = namespace;
}
public void setOutput(Writer writer) {
this.writer = writer;
// elementStack = new String[12]; //nsp/prefix/name
//nspCounts = new int[4];
//nspStack = new String[8]; //prefix/nsp
//indent = new boolean[4];
nspCounts[0] = 2;
nspCounts[1] = 2;
nspStack[0] = "";
nspStack[1] = "";
nspStack[2] = "xml";
nspStack[3] = "http://www.w3.org/XML/1998/namespace";
pending = false;
auto = 0;
depth = 0;
unicode = false;
}
public void setOutput(OutputStream os, String encoding)
throws IOException {
if (os == null)
throw new IllegalArgumentException("os == null");
setOutput(
encoding == null
? new OutputStreamWriter(os)
: new OutputStreamWriter(os, encoding));
this.encoding = encoding;
if (encoding != null && encoding.toLowerCase(Locale.US).startsWith("utf")) {
unicode = true;
}
}
public void startDocument(String encoding, Boolean standalone) throws IOException {
append("<?xml version='1.0' ");
if (encoding != null) {
this.encoding = encoding;
if (encoding.toLowerCase(Locale.US).startsWith("utf")) {
unicode = true;
}
}
if (this.encoding != null) {
append("encoding='");
append(this.encoding);
append("' ");
}
if (standalone != null) {
append("standalone='");
append(standalone.booleanValue() ? "yes" : "no");
append("' ");
}
append("?>");
}
public XmlSerializer startTag(String namespace, String name)
throws IOException {
check(false);
// if (namespace == null)
// namespace = "";
if (indent[depth]) {
append("\r\n");
for (int i = 0; i < depth; i++)
append(" ");
}
int esp = depth * 3;
if (elementStack.length < esp + 3) {
String[] hlp = new String[elementStack.length + 12];
System.arraycopy(elementStack, 0, hlp, 0, esp);
elementStack = hlp;
}
String prefix =
namespace == null
? ""
: getPrefix(namespace, true, true);
if (namespace != null && namespace.isEmpty()) {
for (int i = nspCounts[depth];
i < nspCounts[depth + 1];
i++) {
if (nspStack[i * 2].isEmpty() && !nspStack[i * 2 + 1].isEmpty()) {
throw new IllegalStateException("Cannot set default namespace for elements in no namespace");
}
}
}
elementStack[esp++] = namespace;
elementStack[esp++] = prefix;
elementStack[esp] = name;
append('<');
if (!prefix.isEmpty()) {
append(prefix);
append(':');
}
append(name);
pending = true;
return this;
}
public XmlSerializer attribute(
String namespace,
String name,
String value)
throws IOException {
if (!pending)
throw new IllegalStateException("illegal position for attribute");
// int cnt = nspCounts[depth];
if (namespace == null)
namespace = "";
// depth--;
// pending = false;
String prefix =
namespace.isEmpty()
? ""
: getPrefix(namespace, false, true);
// pending = true;
// depth++;
/* if (cnt != nspCounts[depth]) {
writer.write(' ');
writer.write("xmlns");
if (nspStack[cnt * 2] != null) {
writer.write(':');
writer.write(nspStack[cnt * 2]);
}
writer.write("=\"");
writeEscaped(nspStack[cnt * 2 + 1], '"');
writer.write('"');
}
*/
append(' ');
if (!prefix.isEmpty()) {
append(prefix);
append(':');
}
append(name);
append('=');
char q = value.indexOf('"') == -1 ? '"' : '\'';
append(q);
writeEscaped(value, q);
append(q);
return this;
}
public void flush() throws IOException {
check(false);
flushBuffer();
}
/*
public void close() throws IOException {
check();
writer.close();
}
*/
public XmlSerializer endTag(String namespace, String name)
throws IOException {
if (!pending)
depth--;
// if (namespace == null)
// namespace = "";
if ((namespace == null
&& elementStack[depth * 3] != null)
|| (namespace != null
&& !namespace.equals(elementStack[depth * 3]))
|| !elementStack[depth * 3 + 2].equals(name))
throw new IllegalArgumentException("</{"+namespace+"}"+name+"> does not match start");
if (pending) {
check(true);
depth--;
}
else {
if (indent[depth + 1]) {
append("\r\n");
for (int i = 0; i < depth; i++)
append(" ");
}
append("</");
String prefix = elementStack[depth * 3 + 1];
if (!prefix.isEmpty()) {
append(prefix);
append(':');
}
append(name);
append('>');
}
nspCounts[depth + 1] = nspCounts[depth];
return this;
}
public String getNamespace() {
return getDepth() == 0 ? null : elementStack[getDepth() * 3 - 3];
}
public String getName() {
return getDepth() == 0 ? null : elementStack[getDepth() * 3 - 1];
}
public int getDepth() {
return pending ? depth + 1 : depth;
}
public XmlSerializer text(String text) throws IOException {
check(false);
indent[depth] = false;
writeEscaped(text, -1);
return this;
}
public XmlSerializer text(char[] text, int start, int len)
throws IOException {
text(new String(text, start, len));
return this;
}
public void cdsect(String data) throws IOException {
check(false);
// BEGIN android-changed: ]]> is not allowed within a CDATA,
// so break and start a new one when necessary.
data = data.replace("]]>", "]]]]><![CDATA[>");
append("<![CDATA[");
for (int i = 0; i < data.length(); ++i) {
char ch = data.charAt(i);
boolean allowedInCdata = (ch >= 0x20 && ch <= 0xd7ff) ||
(ch == '\t' || ch == '\n' || ch == '\r') ||
(ch >= 0xe000 && ch <= 0xfffd);
if (allowedInCdata) {
append(ch);
} else if (Character.isHighSurrogate(ch) && i < data.length() - 1) {
// Character entities aren't valid in CDATA, so break out for this.
append("]]>");
writeSurrogate(ch, data.charAt(++i));
append("<![CDATA[");
} else {
reportInvalidCharacter(ch);
}
}
append("]]>");
// END android-changed
}
// BEGIN android-added
private void writeSurrogate(char high, char low) throws IOException {
if (!Character.isLowSurrogate(low)) {
throw new IllegalArgumentException("Bad surrogate pair (U+" + Integer.toHexString((int) high) +
" U+" + Integer.toHexString((int) low) + ")");
}
// Java-style surrogate pairs aren't allowed in XML. We could use the > 3-byte encodings, but that
// seems likely to upset anything expecting modified UTF-8 rather than "real" UTF-8. It seems more
// conservative in a Java environment to use an entity reference instead.
int codePoint = Character.toCodePoint(high, low);
append("&#" + codePoint + ";");
}
// END android-added
public void comment(String comment) throws IOException {
check(false);
append("<!--");
append(comment);
append("-->");
}
public void processingInstruction(String pi)
throws IOException {
check(false);
append("<?");
append(pi);
append("?>");
}
}