org.mentacontainer.util.InjectionUtils Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of menta-container Show documentation
Show all versions of menta-container Show documentation
A IOC container as simple and pragmatic as it can get with programmatic configuration through a Fluent API.
The newest version!
package org.mentacontainer.util;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
@SuppressWarnings({"unchecked", "rawtypes"})
public class InjectionUtils {
/**
* The character used to separate the prefix from the value name when you are using the getObject method with a prefix. You can change the value of this prefix if you want to
* by changing this static variable.
*
* Ex: getObject(User.class, "user") will get all values that begin with "user.".
*/
public static char PREFIX_SEPARATOR = '.';
private static Map, Map> settersMaps = new HashMap, Map>();
private static Map, Map> fieldsMaps = new HashMap, Map>();
public static void prepareForInjection(Class klass, Map setters, Map fields) {
StringBuffer sb = new StringBuffer(32);
Method[] methods = klass.getMethods();
for (int i = 0; i < methods.length; i++) {
Method m = methods[i];
String name = m.getName();
Class[] types = m.getParameterTypes();
if (name.startsWith("set") && name.length() > 3 && types.length == 1) {
String var = name.substring(3);
if (var.length() > 1) {
sb.delete(0, sb.length());
sb.append(var.substring(0, 1).toLowerCase());
sb.append(var.substring(1));
var = sb.toString();
} else {
var = var.toLowerCase();
}
m.setAccessible(true);
if (setters.containsKey(var)) {
Object obj = setters.get(var);
if (obj instanceof List) {
List list = (List) obj;
list.add(m);
} else if (obj instanceof Method) {
List list = new ArrayList();
list.add((Method) obj);
list.add(m);
setters.put(var, list);
}
} else {
setters.put(var, m);
}
}
}
if (fields == null) return;
Field[] f = klass.getDeclaredFields();
for (int i = 0; i < f.length; i++) {
Field field = f[i];
field.setAccessible(true);
String name = field.getName();
if (setters.containsKey(name)) {
Object obj = setters.get(name);
if (obj instanceof Method) {
Method m = (Method) obj;
Class[] types = m.getParameterTypes();
Class type = field.getType();
if (type.isAssignableFrom(types[0])) continue;
} else if (obj instanceof List) {
List list = (List) obj;
Iterator iter = list.iterator();
boolean found = false;
while (iter.hasNext()) {
Method m = iter.next();
Class[] types = m.getParameterTypes();
Class type = field.getType();
if (type.isAssignableFrom(types[0])) {
found = true;
break;
}
}
if (found) continue;
}
}
fields.put(name, field);
}
}
public static boolean checkPrimitives(Class target, Class source) {
if (target.equals(int.class) && source.equals(Integer.class)) return true;
if (target.equals(boolean.class) && source.equals(Boolean.class)) return true;
if (target.equals(byte.class) && source.equals(Byte.class)) return true;
if (target.equals(short.class) && source.equals(Short.class)) return true;
if (target.equals(char.class) && source.equals(Character.class)) return true;
if (target.equals(long.class) && source.equals(Long.class)) return true;
if (target.equals(float.class) && source.equals(Float.class)) return true;
if (target.equals(double.class) && source.equals(Double.class)) return true;
return false;
}
public static Object tryToConvert(Object source, Class targetType) {
return tryToConvert(source, targetType, false);
}
public static Object tryToConvert(Object source, Class targetType, boolean tryNumber) {
String value = null;
if (source instanceof String) {
value = (String) source;
} else if (tryNumber && source instanceof Number) {
value = source.toString();
} else {
return null;
}
Object newValue = null;
String className = targetType.getName();
if (className.equals("int") || className.equals("java.lang.Integer")) {
int x = -1;
try {
x = Integer.parseInt(value);
} catch (Exception e) {
return null;
}
newValue = new Integer(x);
} else if (className.equals("short") || className.equals("java.lang.Short")) {
short x = -1;
try {
x = Short.parseShort(value);
} catch (Exception e) {
return null;
}
newValue = new Short(x);
} else if (className.equals("char") || className.equals("java.lang.Character")) {
if (value.length() != 1) {
return null;
}
newValue = new Character(value.charAt(0));
} else if (className.equals("long") || className.equals("java.lang.Long")) {
long x = -1;
try {
x = Long.parseLong(value);
} catch (Exception e) {
return null;
}
newValue = new Long(x);
} else if (className.equals("float") || className.equals("java.lang.Float")) {
float x = -1;
try {
x = Float.parseFloat(value);
} catch (Exception e) {
return null;
}
newValue = new Float(x);
} else if (className.equals("double") || className.equals("java.lang.Double")) {
double x = -1;
try {
x = Double.parseDouble(value);
} catch (Exception e) {
return null;
}
newValue = new Double(x);
} else if (className.equals("boolean") || className.equals("java.lang.Boolean")) {
try {
int x = Integer.parseInt(value);
if (x == 1) {
newValue = Boolean.TRUE;
} else if (x == 0) {
newValue = Boolean.FALSE;
} else {
return null;
}
} catch (Exception e) {
if (value.equalsIgnoreCase("true") || value.equals("on")) {
newValue = Boolean.TRUE;
} else if (value.equalsIgnoreCase("false")) {
newValue = Boolean.FALSE;
} else {
return null;
}
}
} else if (targetType.isEnum()) {
try {
Class k = (Class) targetType; // not sure how to avoid this raw type!
newValue = Enum.valueOf(k, value);
} catch (Exception e) {
return null;
}
}
return newValue;
}
public static Object shouldConvertToNull(Object value, Class targetType) {
if (targetType.equals(String.class)) {
return value;
} else if (targetType.isPrimitive()) {
return value;
}
return null;
}
public static Class getPrimitiveFrom(Object w) {
if (w instanceof Boolean) {
return Boolean.TYPE;
} else if (w instanceof Byte) {
return Byte.TYPE;
} else if (w instanceof Short) {
return Short.TYPE;
} else if (w instanceof Character) {
return Character.TYPE;
} else if (w instanceof Integer) {
return Integer.TYPE;
} else if (w instanceof Long) {
return Long.TYPE;
} else if (w instanceof Float) {
return Float.TYPE;
} else if (w instanceof Double) {
return Double.TYPE;
}
return null;
}
public static Class getPrimitiveFrom(Class klass) {
String s = klass.getName();
if (s.equals("java.lang.Boolean")) {
return Boolean.TYPE;
} else if (s.equals("java.lang.Byte")) {
return Byte.TYPE;
} else if (s.equals("java.lang.Short")) {
return Short.TYPE;
} else if (s.equals("java.lang.Character")) {
return Character.TYPE;
} else if (s.equals("java.lang.Integer")) {
return Integer.TYPE;
} else if (s.equals("java.lang.Long")) {
return Long.TYPE;
} else if (s.equals("java.lang.Float")) {
return Float.TYPE;
} else if (s.equals("java.lang.Double")) {
return Double.TYPE;
}
return null;
}
public static Field getField(Object target, String name) {
return getField(target.getClass(), name);
}
public static Field getField(Class target, String name) {
Field fields[] = target.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
if (name.equals(fields[i].getName())) {
return fields[i];
}
}
return null;
}
public static String getKeyName(Object obj) {
if (obj instanceof Class) {
Class k = (Class) obj;
String s = k.getSimpleName();
StringBuilder sb = new StringBuilder(s.length());
sb.append(s.substring(0, 1).toLowerCase());
if (s.length() > 1) {
sb.append(s.substring(1));
}
return sb.toString();
}
return obj.toString();
}
public static Method findMethodToGet(Class target, String name) {
StringBuffer sb = new StringBuffer(128);
sb.append("get").append(name.substring(0, 1).toUpperCase());
if (name.length() > 1) sb.append(name.substring(1));
try {
return target.getMethod(sb.toString(), (Class[]) null);
} catch (Exception e) {
}
sb.setLength(0);
sb.append("is").append(name.substring(0, 1).toUpperCase());
if (name.length() > 1) {
sb.append(name.substring(1));
}
try {
return target.getMethod(sb.toString(), (Class[]) null);
} catch (Exception e) {
}
return null;
}
public static Method findMethodToInject(Class target, String name, Class source) {
StringBuffer sb = new StringBuffer(128);
sb.append("set").append(name.substring(0, 1).toUpperCase());
if (name.length() > 1) sb.append(name.substring(1));
String methodName = sb.toString();
Method m = null;
try {
m = FindMethod.getMethod(target, methodName, new Class[] { source });
} catch (Exception e) {
}
if (m == null) {
Class primitive = getPrimitiveFrom(source);
if (primitive != null) {
try {
m = target.getMethod(methodName, new Class[] { primitive });
} catch (Exception e) {
}
}
}
if (m != null) {
m.setAccessible(true);
}
return m;
}
public static Field findFieldToInject(Class target, String name, Class source) {
Field f = getField(target, name);
if (f != null) {
Class type = f.getType();
if (type.isAssignableFrom(source) || checkPrimitives(type, source)) {
f.setAccessible(true);
return f;
}
}
return null;
}
private static final boolean isBlank(Object value) {
if (value != null && value instanceof String) {
String s = ((String) value).trim();
if (s.length() == 0) return true;
}
return false;
}
public static boolean inject(Method m, Object target, Object value, boolean tryToConvert, boolean tryingToConvertBoolean) throws Exception {
Class type = m.getParameterTypes()[0];
if (tryingToConvertBoolean) {
if (value == null && (type.equals(Boolean.class) || type.equals(boolean.class))) {
value = Boolean.FALSE;
} else {
// if trying to convert boolean, convert or don't do anything...
return false;
}
}
if (
value == null
|| (
type.isAssignableFrom(value.getClass()) || checkPrimitives(type, value.getClass()) || (
tryToConvert && (
(isBlank(value) && (value = shouldConvertToNull(value, type)) == null) || (value = tryToConvert(value, type)) != null
)
)
)
) {
try {
m.invoke(target, new Object[] { value });
return true;
} catch (Exception e) {
System.err.println("Error injecting by method: " + value + " in " + target + " thru " + m);
e.printStackTrace();
throw e;
}
}
return false;
}
public static boolean hasDefaultConstructor(Class klass) {
try {
return klass.getConstructor((Class[]) null) != null;
} catch (Exception e) {
return false;
}
}
/**
* Extract the value of a property of a bean!
*
* @param bean
* the target bean
* @param nameProperty
* the property name
* @return they value as String. The method toString is always called to every property!
* @throws Exception
*/
public static String getProperty(Object bean, String nameProperty) throws Exception {
if (nameProperty == null || nameProperty.equals("")) return null;
String methodName = getter(nameProperty);
Class clazz = bean.getClass();
Method[] methods = clazz.getMethods();
for (Method method : methods) {
if (method.getName().equals(methodName) && method.getParameterTypes().length == 0) {
Object value = method.invoke(bean, (Object[]) null);
if (value == null) return null;
return value.toString();
}
}
Field[] fields = clazz.getDeclaredFields();
for (Field field : fields) {
field.setAccessible(true);
if (field.getName().equals(nameProperty)) {
Object value = field.get(bean);
if (value == null) return null;
return value.toString();
}
}
return null;
}
private static String getter(String name) {
StringBuilder sb = new StringBuilder(name.length() + 3);
sb.append("get").append(name.substring(0, 1).toUpperCase());
if (name.length() > 1) sb.append(name.substring(1));
return sb.toString();
}
public static void beanToMap(Object bean, Map map) throws IllegalArgumentException, IllegalAccessException, InvocationTargetException {
if (bean != null) {
for (Method method : bean.getClass().getMethods()) {
String name = method.getName();
if (name.length() > 3 && name.startsWith("get") && !name.equals("getClass") && method.getParameterTypes().length == 0) {
method.setAccessible(true);
Object value = method.invoke(bean, new Object[0]);
map.put(name, value.toString());
}
}
}
}
public static interface Provider {
public Object get(String key);
public boolean hasValue(String key);
}
public static void getObject(Object target, Provider provider, boolean tryField, String prefix, boolean tryToConvert, boolean convertBoolean, boolean allowRecursion)
throws Exception {
Class targetClass = target.getClass();
Map setters, fields;
// see if we have these in cache...
synchronized (settersMaps) {
setters = settersMaps.get(targetClass);
fields = fieldsMaps.get(targetClass);
}
// if not in cache, prepare maps for injection...
if (setters == null) {
setters = new HashMap();
fields = null;
if (tryField) {
fields = new HashMap();
}
prepareForInjection(targetClass, setters, fields);
synchronized (settersMaps) {
settersMaps.put(targetClass, setters);
fieldsMaps.put(targetClass, fields);
}
}
Iterator iter = setters.keySet().iterator();
while (iter.hasNext()) {
String var = iter.next();
boolean hasValue = provider.hasValue(var);
Object value = provider.get(var);
boolean tryingToConvertBoolean = false;
if (value == null && !hasValue) {
if (!convertBoolean) {
continue;
} else {
tryingToConvertBoolean = true;
}
}
// if (value == null) continue;
Object obj = setters.get(var);
// we may have a list of overloaded methods...
List list = null;
Method m = null;
if (obj instanceof List) {
list = (List) obj;
} else {
m = (Method) setters.get(var);
}
if (m != null) {
if (!inject(m, target, value, tryToConvert, tryingToConvertBoolean) && allowRecursion) {
// i did not inject... how about a VO object for this
// setter?
Class type = m.getParameterTypes()[0];
if (!type.getName().startsWith("java.") && !type.isPrimitive() && hasDefaultConstructor(type)) {
Object param = type.newInstance();
InjectionUtils.getObject(param, provider, true, prefix, true, true, false); // no
// recursion...
inject(m, target, param, false, false);
}
}
} else {
Iterator it = list.iterator();
boolean injected = false;
while (it.hasNext()) {
m = it.next();
if (inject(m, target, value, tryToConvert, tryingToConvertBoolean)) {
injected = true;
break;
}
}
if (!injected && allowRecursion) {
// i could not inject anything... how about a VO object for
// this setter...
it = list.iterator();
while (it.hasNext()) {
m = (Method) it.next();
Class type = m.getParameterTypes()[0];
if (!type.getName().startsWith("java.") && !type.isPrimitive() && hasDefaultConstructor(type)) {
Object param = type.newInstance();
InjectionUtils.getObject(param, provider, true, prefix, true, true, false); // no
// recursion...
if (inject(m, target, param, false, false)) {
break; // done...
}
}
}
}
}
}
if (fields != null) {
iter = fields.keySet().iterator();
while (iter.hasNext()) {
String var = iter.next();
boolean hasValue = provider.hasValue(var);
Object value = provider.get(var);
Field f = (Field) fields.get(var);
Class type = f.getType();
// If there is no value in the action input, assume false for
// booleans...
// (checkboxes and radio buttons are not send when not
// marked...)
if (convertBoolean && value == null && !hasValue) {
if (type.equals(Boolean.class) || type.equals(boolean.class)) {
value = Boolean.FALSE;
}
}
if (value == null && !hasValue) continue;
// if (value == null) continue;
if (value == null
|| (type.isAssignableFrom(value.getClass()) || checkPrimitives(type, value.getClass()) || (tryToConvert && ((isBlank(value) && (value = shouldConvertToNull(
value, type)) == null) || (value = tryToConvert(value, type)) != null)))) {
try {
f.set(target, value);
} catch (Exception e) {
System.err.println("Error injecting by field: " + value + " in " + target);
e.printStackTrace();
throw e;
}
}
}
}
}
}