package com.alibaba.fastjson.parser.deserializer;
import java.lang.reflect.Constructor;
import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.Map;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONException;
import com.alibaba.fastjson.parser.DefaultJSONParser;
import com.alibaba.fastjson.parser.Feature;
import com.alibaba.fastjson.parser.JSONLexer;
import com.alibaba.fastjson.parser.JSONToken;
import com.alibaba.fastjson.parser.ParserConfig;
import com.alibaba.fastjson.util.TypeUtils;
public class ThrowableDeserializer extends JavaBeanDeserializer {
public ThrowableDeserializer(ParserConfig mapping, Class<?> clazz){
super(mapping, clazz);
}
@SuppressWarnings("unchecked")
public <T> T deserialze(DefaultJSONParser parser, Type type, Object fieldName) {
JSONLexer lexer = parser.getLexer();
if (lexer.token() == JSONToken.NULL) {
lexer.nextToken();
return null;
}
if (parser.getResolveStatus() == DefaultJSONParser.TypeNameRedirect) {
parser.setResolveStatus(DefaultJSONParser.NONE);
} else {
if (lexer.token() != JSONToken.LBRACE) {
throw new JSONException("syntax error");
}
}
Throwable cause = null;
Class<?> exClass = null;
if (type != null && type instanceof Class) {
Class<?> clazz = (Class<?>) type;
if (Throwable.class.isAssignableFrom(clazz)) {
exClass = clazz;
}
}
String message = null;
StackTraceElement[] stackTrace = null;
Map<String, Object> otherValues = new HashMap<String, Object>();
for (;;) {
// lexer.scanSymbol
String key = lexer.scanSymbol(parser.getSymbolTable());
if (key == null) {
if (lexer.token() == JSONToken.RBRACE) {
lexer.nextToken(JSONToken.COMMA);
break;
}
if (lexer.token() == JSONToken.COMMA) {
if (lexer.isEnabled(Feature.AllowArbitraryCommas)) {
continue;
}
}
}
lexer.nextTokenWithColon(JSONToken.LITERAL_STRING);
if (JSON.DEFAULT_TYPE_KEY.equals(key)) {
if (lexer.token() == JSONToken.LITERAL_STRING) {
String exClassName = lexer.stringVal();
exClass = TypeUtils.loadClass(exClassName);
} else {
throw new JSONException("syntax error");
}
lexer.nextToken(JSONToken.COMMA);
} else if ("message".equals(key)) {
if (lexer.token() == JSONToken.NULL) {
message = null;
} else if (lexer.token() == JSONToken.LITERAL_STRING) {
message = lexer.stringVal();
} else {
throw new JSONException("syntax error");
}
lexer.nextToken();
} else if ("cause".equals(key)) {
cause = deserialze(parser, null, "cause");
} else if ("stackTrace".equals(key)) {
stackTrace = parser.parseObject(StackTraceElement[].class);
} else {
// TODO
otherValues.put(key, parser.parse());
}
if (lexer.token() == JSONToken.COMMA) {
continue;
}
if (lexer.token() == JSONToken.RBRACE) {
lexer.nextToken(JSONToken.COMMA);
break;
}
}
Throwable ex = null;
if (exClass == null) {
ex = new Exception(message, cause);
} else {
try {
ex = createException(message, cause, exClass);
if (ex == null) {
ex = new Exception(message, cause);
}
} catch (Exception e) {
throw new JSONException("create instance error", e);
}
}
if (stackTrace != null) {
ex.setStackTrace(stackTrace);
}
return (T) ex;
}
private Throwable createException(String message, Throwable cause, Class<?> exClass) throws Exception {
Constructor<?> defaultConstructor = null;
Constructor<?> messageConstructor = null;
Constructor<?> causeConstructor = null;
for (Constructor<?> constructor : exClass.getConstructors()) {
if (constructor.getParameterTypes().length == 0) {
defaultConstructor = constructor;
continue;
}
if (constructor.getParameterTypes().length == 1 && constructor.getParameterTypes()[0] == String.class) {
messageConstructor = constructor;
continue;
}
if (constructor.getParameterTypes().length == 2 && constructor.getParameterTypes()[0] == String.class
&& constructor.getParameterTypes()[1] == Throwable.class) {
causeConstructor = constructor;
continue;
}
}
if (causeConstructor != null) {
return (Throwable) causeConstructor.newInstance(message, cause);
}
if (messageConstructor != null) {
return (Throwable) messageConstructor.newInstance(message);
}
if (defaultConstructor != null) {
return (Throwable) defaultConstructor.newInstance();
}
return null;
}
public int getFastMatchToken() {
return JSONToken.LBRACE;
}
}