/** Set the value for the key in this context. */
public <T> void put(Key<T> key, T data) {
DEBUG.P(this, "put(Key<T> key, T data)");
if (data != null) DEBUG.P("data=" + data.getClass().getName());
else DEBUG.P("data=" + data);
// DEBUG.P("context前="+toString());
/*例如:
Context context = new Context();
Context.Key<Context.Factory> factoryKey =new Context.Key<Context.Factory>();
context.put(factoryKey,new Context.Factory<String>(){public String make() {return "";}});
出现如下类似异常:
Exception in thread "main" java.lang.AssertionError: T extends Context.Factory
因为Context.Key<T>的参数化类型不允许是Context.Key<Context.Factory>
*/
if (data instanceof Factory) throw new AssertionError("T extends Context.Factory");
checkState(ht);
Object old = ht.put(key, data);
if (old != null && !(old instanceof Factory) && old != data && data != null)
throw new AssertionError("duplicate context value");
DEBUG.P("context后=" + toString());
DEBUG.P(0, this, "put(Key<T> key, T data)");
}
protected Enter(Context context) {
DEBUG.P(this,"Enter(1)");
context.put(enterKey, this);
log = Log.instance(context);
reader = ClassReader.instance(context);
make = TreeMaker.instance(context);
syms = Symtab.instance(context);
chk = Check.instance(context);
memberEnter = MemberEnter.instance(context);
annotate = Annotate.instance(context);
lint = Lint.instance(context);
predefClassDef = make.ClassDef(
make.Modifiers(PUBLIC),
syms.predefClass.name, null, null, null, null);
//predefClass是一个ClassSymbol(PUBLIC|ACYCLIC, names.empty, rootPackage)
//且它的Scope members_field已有成员(几个基本类型符号(symbols for basic types)及其他操作符)
//请参考Systab类的predefClass字段说明
predefClassDef.sym = syms.predefClass;
todo = Todo.instance(context);
fileManager = context.get(JavaFileManager.class);
names = Name.Table.instance(context); //我加上的
DEBUG.P(0,this,"Enter(1)");
}
private TypeHandler resolveTypeHandler(
TypeHandlerFactory typeHandlerFactory,
Class clazz,
String propertyName,
String javaType,
String jdbcType) {
try { // 我加上的
DEBUG.P(this, "resolveTypeHandler(5)");
TypeHandler handler = null;
if (clazz == null) {
// Unknown
handler = typeHandlerFactory.getUnkownTypeHandler();
} else if (DomTypeMarker.class.isAssignableFrom(clazz)) {
// DOM
handler = typeHandlerFactory.getTypeHandler(String.class, jdbcType);
} else if (java.util.Map.class.isAssignableFrom(clazz)) {
// Map
if (javaType == null) {
handler =
typeHandlerFactory
.getUnkownTypeHandler(); // BUG 1012591 -
// typeHandlerFactory.getTypeHandler(java.lang.Object.class, jdbcType);
} else {
try {
javaType = typeHandlerFactory.resolveAlias(javaType);
Class javaClass = Resources.classForName(javaType);
handler = typeHandlerFactory.getTypeHandler(javaClass, jdbcType);
} catch (Exception e) {
throw new SqlMapException("Error. Could not set TypeHandler. Cause: " + e, e);
}
}
} else if (typeHandlerFactory.getTypeHandler(clazz, jdbcType) != null) {
// Primitive
handler = typeHandlerFactory.getTypeHandler(clazz, jdbcType);
} else {
// JavaBean
if (javaType == null) {
Class type = PROBE.getPropertyTypeForGetter(clazz, propertyName);
handler = typeHandlerFactory.getTypeHandler(type, jdbcType);
} else {
try {
javaType = typeHandlerFactory.resolveAlias(javaType);
Class javaClass = Resources.classForName(javaType);
handler = typeHandlerFactory.getTypeHandler(javaClass, jdbcType);
} catch (Exception e) {
throw new SqlMapException("Error. Could not set TypeHandler. Cause: " + e, e);
}
}
}
return handler;
} finally { // 我加上的
DEBUG.P(0, this, "resolveTypeHandler(5)");
}
}
public <T> void put(Class<T> clazz, Factory<T> fac) {
DEBUG.P(this, "put(Class<T> clazz, Factory<T> fac)");
if (fac != null) DEBUG.P("fac=" + fac.getClass().getName());
else DEBUG.P("fac=" + fac);
// DEBUG.P("context前="+toString());
put(key(clazz), fac);
// DEBUG.P("context后="+toString());
DEBUG.P(0, this, "put(Class<T> clazz, Factory<T> fac)");
}
public <T> void put(Class<T> clazz, T data) {
DEBUG.P(this, "put(Class<T> clazz, T data)");
if (data != null) DEBUG.P("data=" + data.getClass().getName());
else DEBUG.P("data=" + data);
// DEBUG.P("context前="+toString());
put(key(clazz), data);
// DEBUG.P("context后="+toString());
DEBUG.P(0, this, "put(Class<T> clazz, T data)");
}
public SqlText parseInlineParameterMap(
TypeHandlerFactory typeHandlerFactory, String sqlStatement) {
try { // 我加上的
DEBUG.P(this, "parseInlineParameterMap(2)");
return parseInlineParameterMap(typeHandlerFactory, sqlStatement, null);
} finally { // 我加上的
DEBUG.P(0, this, "parseInlineParameterMap(2)");
}
}
public <T> T get(Class<T> clazz) {
try {
DEBUG.P(this, "get(Class<T> clazz)");
if (clazz != null) DEBUG.P("clazz=" + clazz.getName());
else DEBUG.P("clazz=" + clazz);
return get(key(clazz));
} finally {
DEBUG.P(0, this, "get(Class<T> clazz)");
}
}
/** Set the factory for the key in this context. */
public <T> void put(Key<T> key, Factory<T> fac) {
DEBUG.P(this, "put(Key<T> key, Factory<T> fac)");
// DEBUG.P("context前="+toString())
if (fac != null) DEBUG.P("fac=" + fac.getClass().getName());
else DEBUG.P("fac=" + fac);
checkState(ht);
Object old = ht.put(key, fac);
if (old != null) throw new AssertionError("duplicate context value");
DEBUG.P("context后=" + toString());
DEBUG.P(0, this, "put(Key<T> key, Factory<T> fac)");
}
/** Default constructor */
public SessionScope() {
try { // 我加上的
DEBUG.P(this, "SessionScope()");
this.preparedStatements = new HashMap();
this.inBatch = false;
this.requestStackDepth = 0;
this.id = getNextId();
DEBUG.P("this.id=" + this.id);
} finally { // 我加上的
DEBUG.P(0, this, "SessionScope()");
}
}
public ServerErrorMessage(String p_serverError, int verbosity) {
try { // 我加上的
DEBUG.P(this, "ServerErrorMessage(2)");
DEBUG.P("p_serverError=" + p_serverError);
DEBUG.P("verbosity=" + verbosity);
this.verbosity = verbosity;
char[] l_chars = p_serverError.toCharArray();
int l_pos = 0;
int l_length = l_chars.length;
while (l_pos < l_length) {
char l_mesgType = l_chars[l_pos];
if (l_mesgType != '\0') {
l_pos++;
int l_startString = l_pos;
while (l_chars[l_pos] != '\0' && l_pos < l_length) {
l_pos++;
}
String l_mesgPart = new String(l_chars, l_startString, l_pos - l_startString);
m_mesgParts.put(new Character(l_mesgType), l_mesgPart);
DEBUG.P("l_mesgPart=" + l_mesgPart);
DEBUG.P("m_mesgParts=" + m_mesgParts);
}
l_pos++;
}
DEBUG.P("m_mesgParts=" + m_mesgParts);
} finally { // 我加上的
DEBUG.P(0, this, "ServerErrorMessage(2)");
}
}
private <T> Key<T> key(Class<T> clss) {
DEBUG.P(this, "key(Class<T> clss)");
if (clss != null) DEBUG.P("clss=" + clss.getName());
else DEBUG.P("clss=" + clss);
checkState(kt);
// 等价于Key<T> k = Context.<Key<T>>uncheckedCast(kt.get(clss));
// 因为kt.get(clss)返回的类型是Key<T>，刚好与等式左边的类型一样
Key<T> k = uncheckedCast(kt.get(clss));
DEBUG.P("k=" + k);
if (k == null) {
k = new Key<T>();
kt.put(clss, k);
}
DEBUG.P(0, this, "key(Class<T> clss)");
return k;
}
/** Get the value for the key in this context. */
public <T> T get(Key<T> key) {
try {
DEBUG.P(this, "get(Key<T> key)");
// if(key!=null) DEBUG.P("key="+key.getClass().getName());
// else DEBUG.P("key="+key);
DEBUG.P("key=" + key);
checkState(ht);
Object o = ht.get(key);
if (o != null) DEBUG.P("o=" + o.getClass().getName());
else DEBUG.P("o=" + o);
DEBUG.P("(o instanceof Factory)=" + (o instanceof Factory));
if (o instanceof Factory) {
Factory fac = (Factory) o;
o = fac.make();
if (o instanceof Factory) throw new AssertionError("T extends Context.Factory");
// 也就是说在调用make()时已把make()返回的结果放入ht(例子见:JavacFileManager.preRegister())
assert ht.get(key) == o;
}
/* The following cast can't fail unless there was
* cheating elsewhere, because of the invariant on ht.
* Since we found a key of type Key<T>, the value must
* be of type T.
*/
return Context.<T>uncheckedCast(o);
} finally {
DEBUG.P(0, this, "get(Key<T> key)");
}
/*
注意这里的“<T>”与 “private static <T> T uncheckedCast(Object o)”中
的“<T>”的差别，前者表示的是get(Key<T> key)方法中的“T”的实际类型，
假设最开始:
-------------------------------------
Context context = new Context();
Context.Key<Number> numberKey = new Context.Key<Number>();
Number number=new Number();
context.put(numberKey,number);
number=context.get(numberKey);
------------------------------------
这时把“numberKey”传进“get(Key<T> key)”方法，
因为参数“numberKey”是“Context.Key<Number>”类型，
所以get(Key<T> key)中的“T”的实际类型是“Number”。
但是“get(Key<T> key)”方法里的“Object o = ht.get(key)”，
变量“o”是Object类型的，必需调用“Context.<T>uncheckedCast(o)”将
变量“o”引用的Object实例转换成“Number”类型，
这样“number=context.get(numberKey)”得到的结果才正确。
“Context.<T>uncheckedCast(o)”相当于把“Object o”转换成“<T>”(这里就是Number)
像“Context.<T>uncheckedCast(o)”这种语法确实很古怪，
这主要是由于“private static <T> T uncheckedCast(Object o)”方法的定义
造成的，这个方法是一个静态泛型方法，而且只有返回类型与泛型变量“<T>”相关，
方法参数只有( Object o )，并且不与泛型变量“<T>”相关，
当要调用uncheckedCast方法时，可以用下面的格式调用它:
Context.<返回值类型>uncheckedCast(参数Object o)
返回值类型可以是泛型变量
(泛型变量的实际类型在编译期间只能推断它的上限绑定，
具体是什么类型只能在运行期间确定)
假设最开始:
Object o=new String("str");
那么可以这样调用它:
String str=Context.<String>uncheckedCast(o);(等价于: String str=(String)o)
把“return Context.<T>uncheckedCast(o);”与uncheckedCast方法的调用格式对照
“<T>”对应“<返回值类型>”，“(o)”对应“(参数Object o)”
另外“uncheckedCast”方法的定义如下:
--------------------------------------
@SuppressWarnings("unchecked")
private static <T> T uncheckedCast(Object o) {
return (T)o;
}
--------------------------------------
注释“@SuppressWarnings("unchecked")”间接指出了uncheckedCast方法会在
运行时有可能产生转换异常(java.lang.ClassCastException)，
因为(T)的类型是未确定的，
比如(T)的类型可能是“Number”，当参数(Object o)实际是String的实例引用时，
这时“(T)o”就等价于“(Number)String”，显然是不对的。
*/
}
public SqlText parseInlineParameterMap(
TypeHandlerFactory typeHandlerFactory, String sqlStatement, Class parameterClass) {
try { // 我加上的
DEBUG.P(this, "parseInlineParameterMap(3)");
DEBUG.P("sqlStatement=" + sqlStatement);
DEBUG.P("parameterClass=" + parameterClass);
String newSql = sqlStatement;
List mappingList = new ArrayList();
// 第三个参数为true，表示把分隔符PARAMETER_TOKEN("#")也返回
StringTokenizer parser = new StringTokenizer(sqlStatement, PARAMETER_TOKEN, true);
StringBuffer newSqlBuffer = new StringBuffer();
String token = null;
String lastToken = null;
while (parser.hasMoreTokens()) {
token = parser.nextToken();
DEBUG.P("lastToken=" + lastToken);
DEBUG.P("token=" + token);
if (PARAMETER_TOKEN.equals(lastToken)) {
if (PARAMETER_TOKEN.equals(token)) {
// 连续的两个#代表一个"#"字符
// 如:select * from ACCOUNT where ACC_FIRST_NAME = "##"
// 实际是: select * from ACCOUNT where ACC_FIRST_NAME = "#"
newSqlBuffer.append(PARAMETER_TOKEN);
token = null;
} else {
ParameterMapping mapping = null;
if (token.indexOf(PARAM_DELIM) > -1) {
mapping = oldParseMapping(token, parameterClass, typeHandlerFactory);
} else {
mapping = newParseMapping(token, parameterClass, typeHandlerFactory);
}
mappingList.add(mapping);
newSqlBuffer.append("?");
token = parser.nextToken();
DEBUG.P("token2=" + token);
if (!PARAMETER_TOKEN.equals(token)) {
throw new SqlMapException(
"Unterminated inline parameter in mapped statement ("
+ "statement.getId()"
+ ").");
}
token = null;
}
} else {
if (!PARAMETER_TOKEN.equals(token)) {
newSqlBuffer.append(token);
}
}
lastToken = token;
}
newSql = newSqlBuffer.toString();
DEBUG.P(1);
DEBUG.P("newSql=" + newSql);
ParameterMapping[] mappingArray =
(ParameterMapping[]) mappingList.toArray(new ParameterMapping[mappingList.size()]);
DEBUG.PA("mappingArray", mappingArray);
SqlText sqlText = new SqlText();
sqlText.setText(newSql);
sqlText.setParameterMappings(mappingArray);
return sqlText;
} finally { // 我加上的
DEBUG.P(0, this, "parseInlineParameterMap(3)");
}
}
private ParameterMapping oldParseMapping(
String token, Class parameterClass, TypeHandlerFactory typeHandlerFactory) {
try { // 我加上的
DEBUG.P(this, "oldParseMapping(3)");
ParameterMapping mapping = new ParameterMapping();
if (token.indexOf(PARAM_DELIM) > -1) {
StringTokenizer paramParser = new StringTokenizer(token, PARAM_DELIM, true);
int n1 = paramParser.countTokens();
if (n1 == 3) {
String name = paramParser.nextToken();
paramParser.nextToken(); // ignore ":"
String type = paramParser.nextToken();
mapping.setPropertyName(name);
mapping.setJdbcTypeName(type);
TypeHandler handler;
if (parameterClass == null) {
handler = typeHandlerFactory.getUnkownTypeHandler();
} else {
handler = resolveTypeHandler(typeHandlerFactory, parameterClass, name, null, type);
}
mapping.setTypeHandler(handler);
return mapping;
} else if (n1 >= 5) {
String name = paramParser.nextToken();
paramParser.nextToken(); // ignore ":"
String type = paramParser.nextToken();
paramParser.nextToken(); // ignore ":"
String nullValue = paramParser.nextToken();
while (paramParser.hasMoreTokens()) {
nullValue = nullValue + paramParser.nextToken();
}
mapping.setPropertyName(name);
mapping.setJdbcTypeName(type);
mapping.setNullValue(nullValue);
TypeHandler handler;
if (parameterClass == null) {
handler = typeHandlerFactory.getUnkownTypeHandler();
} else {
handler = resolveTypeHandler(typeHandlerFactory, parameterClass, name, null, type);
}
mapping.setTypeHandler(handler);
return mapping;
} else {
throw new SqlMapException("Incorrect inline parameter map format: " + token);
}
} else {
mapping.setPropertyName(token);
TypeHandler handler;
if (parameterClass == null) {
handler = typeHandlerFactory.getUnkownTypeHandler();
} else {
handler = resolveTypeHandler(typeHandlerFactory, parameterClass, token, null, null);
}
mapping.setTypeHandler(handler);
return mapping;
}
} finally { // 我加上的
DEBUG.P(0, this, "oldParseMapping(3)");
}
}
private ParameterMapping newParseMapping(
String token, Class parameterClass, TypeHandlerFactory typeHandlerFactory) {
try { // 我加上的
DEBUG.P(this, "newParseMapping(3)");
DEBUG.P("token=" + token);
DEBUG.P("parameterClass=" + parameterClass);
ParameterMapping mapping = new ParameterMapping();
// #propertyName,javaType=string,jdbcType=VARCHAR,mode=IN,nullValue=N/A,handler=string,numericScale=2#
StringTokenizer paramParser = new StringTokenizer(token, "=,", false);
mapping.setPropertyName(paramParser.nextToken());
while (paramParser.hasMoreTokens()) {
String field = paramParser.nextToken();
if (paramParser.hasMoreTokens()) {
String value = paramParser.nextToken();
if ("javaType".equals(field)) {
value = typeHandlerFactory.resolveAlias(value);
mapping.setJavaTypeName(value);
} else if ("jdbcType".equals(field)) {
mapping.setJdbcTypeName(value);
} else if ("mode".equals(field)) {
mapping.setMode(value);
} else if ("nullValue".equals(field)) {
mapping.setNullValue(value);
} else if ("handler".equals(field)) {
try {
value = typeHandlerFactory.resolveAlias(value);
Object impl = Resources.instantiate(value);
if (impl instanceof TypeHandlerCallback) {
mapping.setTypeHandler(new CustomTypeHandler((TypeHandlerCallback) impl));
} else if (impl instanceof TypeHandler) {
mapping.setTypeHandler((TypeHandler) impl);
} else {
throw new SqlMapException(
"The class "
+ value
+ " is not a valid implementation of TypeHandler or TypeHandlerCallback");
}
} catch (Exception e) {
throw new SqlMapException(
"Error loading class specified by handler field in " + token + ". Cause: " + e,
e);
}
} else if ("numericScale".equals(field)) {
try {
Integer numericScale = Integer.valueOf(value);
if (numericScale.intValue() < 0) {
throw new SqlMapException(
"Value specified for numericScale must be greater than or equal to zero");
}
mapping.setNumericScale(numericScale);
} catch (NumberFormatException e) {
throw new SqlMapException("Value specified for numericScale is not a valid Integer");
}
} else {
throw new SqlMapException(
"Unrecognized parameter mapping field: '" + field + "' in " + token);
}
} else {
throw new SqlMapException(
"Incorrect inline parameter map format (missmatched name=value pairs): " + token);
}
}
if (mapping.getTypeHandler() == null) {
TypeHandler handler;
if (parameterClass == null) {
handler = typeHandlerFactory.getUnkownTypeHandler();
} else {
handler =
resolveTypeHandler(
typeHandlerFactory,
parameterClass,
mapping.getPropertyName(),
mapping.getJavaTypeName(),
mapping.getJdbcTypeName());
}
mapping.setTypeHandler(handler);
}
return mapping;
} finally { // 我加上的
DEBUG.P(0, this, "newParseMapping(3)");
}
}