[英]Java support for non-BMP Unicode characters (i.e. codepoints > 0xFFFF) in their Regular Expression Library?
[英]Java XMLStreamWriter: Outputting Unicode extended characters (non-BMP)
有誰知道如何使用Java的XMLStreamWriter正確輸出擴展字符(非BMP,大於1個char
)? 例如,嘗試輸出Unicode U + 𐒀
:
import java.io.OutputStreamWriter;
import java.nio.charset.StandardCharsets;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
public class XmlStreamWriterExtendedCharactersFail {
public static void main(String[] args) throws XMLStreamException {
String inlineStr = "inlineStr = 𐒀";
// create string using StringBuilder to avoid Java file encoding confusion:
String sbStr = new StringBuilder("sbStr = ").appendCodePoint(0x10480).toString();
assert sbStr.equals(inlineStr);
System.out.println(sbStr);
OutputStreamWriter outWriter = new OutputStreamWriter(System.out,
StandardCharsets.UTF_8.newEncoder());
XMLStreamWriter writer = XMLOutputFactory.newFactory()
.createXMLStreamWriter(outWriter);
writer.writeStartDocument("UTF-8", "1.1");
writer.writeStartElement("el");
writer.writeCharacters(sbStr);
writer.writeEndElement();
writer.writeEndDocument();
writer.close();
}
}
結果是:
sbStr = 𐒀
<?xml version="1.1" encoding="UTF-8"?><el>sbStr = ��</el>
請注意, ��
是無效的代碼點,並且在使用SAX進行解析時將導致錯誤。
預期產量:
sbStr = 𐒀
<?xml version="1.1" encoding="UTF-8"?><el>sbStr = 𐒀</el>
sbStr = ⣰
也會在緊要關頭做,但首先是可取的。
請注意,Apache Commons的StringEscapeUtils.escapeXML
在3.0版之前也存在此問題。
我圍繞XMLStreamWriter創建了以下包裝器,以解決問題。 它使用Apache Commons轉義字符數據,並將其直接寫入基礎Writer
。
import java.io.IOException;
import java.io.Writer;
import java.nio.CharBuffer;
import javax.xml.namespace.NamespaceContext;
import javax.xml.stream.FactoryConfigurationError;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import org.apache.commons.lang3.StringEscapeUtils;
import org.apache.commons.lang3.text.translate.CharSequenceTranslator;
public class UnicodeXMLStreamWriter implements XMLStreamWriter {
private XMLStreamWriter xmlSW;
private Writer writer;
private CharSequenceTranslator characterEscapor = StringEscapeUtils.ESCAPE_XML11;
public static UnicodeXMLStreamWriter newInstance(Writer writer) throws XMLStreamException, FactoryConfigurationError {
return newInstance(writer, XMLOutputFactory.newFactory());
}
public static UnicodeXMLStreamWriter newInstance(Writer writer, XMLOutputFactory factory) throws XMLStreamException {
XMLStreamWriter xmlSW = factory.createXMLStreamWriter(writer);
return new UnicodeXMLStreamWriter(writer, xmlSW);
}
public UnicodeXMLStreamWriter(Writer writer, XMLStreamWriter xmlSW) {
this.writer = writer;
this.xmlSW = xmlSW;
}
public void writeCharacters(String text) throws XMLStreamException {
// finish writing start element
xmlSW.writeCharacters("");
xmlSW.flush();
try {
characterEscapor.translate(text, writer);
} catch (IOException e) {
throw new XMLStreamException(e);
}
}
public void writeCharacters(char[] text, int start, int len)
throws XMLStreamException {
// finish writing start element
xmlSW.writeCharacters("");
xmlSW.flush();
try {
characterEscapor.translate(CharBuffer.wrap(text, start, len), writer);
} catch (IOException e) {
throw new XMLStreamException(e);
}
}
//////////////// REMAINING METHODS ARE DELEGATES to xmlSW ////////////////
public void writeStartElement(String localName) throws XMLStreamException {
xmlSW.writeStartElement(localName);
}
public void writeStartElement(String namespaceURI, String localName)
throws XMLStreamException {
xmlSW.writeStartElement(namespaceURI, localName);
}
public void writeStartElement(String prefix, String localName,
String namespaceURI) throws XMLStreamException {
xmlSW.writeStartElement(prefix, localName, namespaceURI);
}
public void writeEmptyElement(String namespaceURI, String localName)
throws XMLStreamException {
xmlSW.writeEmptyElement(namespaceURI, localName);
}
public void writeEmptyElement(String prefix, String localName,
String namespaceURI) throws XMLStreamException {
xmlSW.writeEmptyElement(prefix, localName, namespaceURI);
}
public void writeEmptyElement(String localName) throws XMLStreamException {
xmlSW.writeEmptyElement(localName);
}
public void writeEndElement() throws XMLStreamException {
xmlSW.writeEndElement();
}
public void writeEndDocument() throws XMLStreamException {
xmlSW.writeEndDocument();
}
public void close() throws XMLStreamException {
xmlSW.close();
}
public void flush() throws XMLStreamException {
xmlSW.flush();
}
public void writeAttribute(String localName, String value)
throws XMLStreamException {
xmlSW.writeAttribute(localName, value);
}
public void writeAttribute(String prefix, String namespaceURI,
String localName, String value) throws XMLStreamException {
xmlSW.writeAttribute(prefix, namespaceURI, localName, value);
}
public void writeAttribute(String namespaceURI, String localName,
String value) throws XMLStreamException {
xmlSW.writeAttribute(namespaceURI, localName, value);
}
public void writeNamespace(String prefix, String namespaceURI)
throws XMLStreamException {
xmlSW.writeNamespace(prefix, namespaceURI);
}
public void writeDefaultNamespace(String namespaceURI)
throws XMLStreamException {
xmlSW.writeDefaultNamespace(namespaceURI);
}
public void writeComment(String data) throws XMLStreamException {
xmlSW.writeComment(data);
}
public void writeProcessingInstruction(String target)
throws XMLStreamException {
xmlSW.writeProcessingInstruction(target);
}
public void writeProcessingInstruction(String target, String data)
throws XMLStreamException {
xmlSW.writeProcessingInstruction(target, data);
}
public void writeCData(String data) throws XMLStreamException {
xmlSW.writeCData(data);
}
public void writeDTD(String dtd) throws XMLStreamException {
xmlSW.writeDTD(dtd);
}
public void writeEntityRef(String name) throws XMLStreamException {
xmlSW.writeEntityRef(name);
}
public void writeStartDocument() throws XMLStreamException {
xmlSW.writeStartDocument();
}
public void writeStartDocument(String version) throws XMLStreamException {
xmlSW.writeStartDocument(version);
}
public void writeStartDocument(String encoding, String version)
throws XMLStreamException {
xmlSW.writeStartDocument(encoding, version);
}
public String getPrefix(String uri) throws XMLStreamException {
return xmlSW.getPrefix(uri);
}
public void setPrefix(String prefix, String uri) throws XMLStreamException {
xmlSW.setPrefix(prefix, uri);
}
public void setDefaultNamespace(String uri) throws XMLStreamException {
xmlSW.setDefaultNamespace(uri);
}
public void setNamespaceContext(NamespaceContext context)
throws XMLStreamException {
xmlSW.setNamespaceContext(context);
}
public NamespaceContext getNamespaceContext() {
return xmlSW.getNamespaceContext();
}
public Object getProperty(String name) throws IllegalArgumentException {
return xmlSW.getProperty(name);
}
}
使用此將產生所需的輸出。 現在要提交錯誤報告...
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