Java Primitives類代碼示例

import com.google.common.primitives.Primitives; //導入依賴的package包/類
/**
 * Gets the data type most relevant to a Java class.
 */
@SuppressWarnings("unchecked")
public <T> Optional<DataType<T>> forJavaType(Class<T> type) {
  if (type.isPrimitive()) {
    return forJavaType((Class) Primitives.wrap(type));
  }
  return (Optional) typeCache.computeIfAbsent(type, __ -> {
    if (DataType.class.isAssignableFrom(type)) {
      return forType((Class<DataType>) type);
    }
    Optional<DataType> naive = dataTypes.values().stream()
        .filter(t -> type.equals(t.getJavaClass()))
        .findAny();
    if (naive.isPresent()) {
      return naive;
    } else {
      // Check Java class hierarchy
      Comparator<Class<?>> classComparator = closestTo(type);
      // This stream MUST be sequential to work correctly
      return dataTypes.values().stream()
          .filter(t -> t != All)
          .sorted((t1, t2) -> classComparator.reversed().compare(t1.getJavaClass(), t2.getJavaClass()))
          .findFirst();
    }
  });
}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
public static final Method findMethod(Class<?> clazz, InvocationParametersBean invocation) throws NoSuchMethodException {
    Method ret = null;
    Class<?>[] types = getParameterTypes(invocation);
    try {
        ret = clazz.getMethod(invocation.getMethodName(), types);
    } catch (NoSuchMethodException e) {
    }
    if (ret == null && types != null) {
        int max = types.length;
        for (int i = 0; i < max; i++) {
            if (Primitives.isWrapperType(types[i])) {
                types[i] = Primitives.unwrap(types[i]);
            }
        }
        ret = clazz.getMethod(invocation.getMethodName(), types);
    }
    return ret;
}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
private static <T> T cast(final Object value, final Class<T> expectedType) {
    if (value == null) {
        return null;
    }

    if (expectedType.isPrimitive() && Primitives.wrap(expectedType).equals(value.getClass())) {
        @SuppressWarnings("unchecked")
        final T castValue = (T) value;
        return castValue;
    }

    if (!expectedType.isAssignableFrom(value.getClass())) {
        throw new IllegalArgumentException(String.format(
                "Expected %s, but was: %s", expectedType.getName(), value.getClass().getName()));
    }

    return expectedType.cast(value);
}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
public static Method getValueOfMethodFrom(Class returnClass) {
    val existsMethod = valueOfMethodCache.get(returnClass);
    if (existsMethod != null) return existsMethod.orNull();

    val clazz = Primitives.wrap(returnClass);
    try {
        val valueOfMethod = clazz.getMethod("valueOf", String.class);
        if (isPublicStatic(clazz, valueOfMethod)) {
            valueOfMethodCache.put(returnClass, Optional.of(valueOfMethod));
            return valueOfMethod;
        }
    } catch (Exception e) {
        valueOfMethodCache.put(returnClass, Optional.<Method>absent());
    }

    return null;
}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
/**
 * Determines whether a value is 'true', where true is interpreted depending on the values
 * type.
 */
@SuppressWarnings("rawtypes")
static boolean isTrue(Object v1) {
  if (v1 instanceof Number) {
    // For numbers, compare with  the default value (zero), which we obtain by
    // creating an array.
    return !Array.get(Array.newInstance(Primitives.unwrap(v1.getClass()), 1), 0).equals(v1);
  }
  if (v1 instanceof Boolean) {
    return (Boolean) v1;
  }
  if (v1 instanceof Doc) {
    return !((Doc) v1).isWhitespace();
  }
  if (v1 instanceof String) {
    return !Strings.isNullOrEmpty((String) v1);
  }
  if (v1 instanceof Iterable) {
    return ((Iterable) v1).iterator().hasNext();
  }
  return false;
}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
static String reAssignContainers(Class<?>[] paramTypes) {
	StringBuilder stringBuilder = new StringBuilder();
	int i = 0;
	for (Class<?> c : paramTypes) {
		stringBuilder.append("param").append(i).append(" = (");
		if (c.isPrimitive()) {
			Class<?> wrapped = Primitives.wrap(c);
			stringBuilder
					.append("(").append(wrapped.getCanonicalName()).append(") $mArgs[").append(i).append("]).")
					.append(c.getCanonicalName()).append("Value();\n");// <-- This feels so cheaty
		} else {
			stringBuilder.append(c.getCanonicalName()).append(") $mArgs[").append(i).append("];\n");
		}
		i++;
	}
	return stringBuilder.toString();
}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
@SuppressWarnings("unchecked")
protected static <X> X itemFromString(String value, Class<X> clazz, Flag flag)
    throws FlagException {
  // In case we get a primitive type (e.g. from Scala), get the boxed version to know
  // how to serialize.
  clazz = Primitives.wrap(clazz);
  if (Number.class.isAssignableFrom(clazz)) {
    return clazz.cast(PrimitiveFlagField.NumberFlagField.fromString(value, clazz, flag));
  } else if (Boolean.class.isAssignableFrom(clazz)) {
    return clazz.cast(Boolean.valueOf(value));
  } else if (String.class.isAssignableFrom(clazz)) {
    return clazz.cast(value);
  } else if (clazz.isEnum()) {
    return (X) PrimitiveFlagField.EnumFlagField.fromString(value, (Class<Enum>) clazz, flag);
  }
  throw new FlagException.UnsupportedType(flag, clazz);
}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
@Test
public void testBoxedPrimitives() {
	// boxed primitives cannot be null otherwise we get NPE when unboxing
	ImmutableMap<Class<?>, String> defaultValueMap = ImmutableMap.<Class<?>, String> builder()
			.put(Byte.class, "0").put(Short.class, "0").put(Integer.class, "0")
			.put(Long.class, "0L").put(Float.class, "0.0F").put(Double.class, "0.0D")
			.put(Character.class, "\'a\'").put(Boolean.class, "false").build();

	RetainedTestField[] fields = defaultValueMap.entrySet()
			.stream().map(ent -> new RetainedTestField(ent.getKey(),
					"_" + ent.getKey().getSimpleName(), ent.getValue()))
			.toArray(RetainedTestField[]::new);
	// comparison between primitives and boxed primitives does not work,
	// manually wrap it
	testTypes(ALWAYS, (field, type, arguments) -> type.isPrimitive()
			&& field.clazz == Primitives.wrap(type), f->1, fields);

}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
private void setLocalConverter(FieldConverterMapper converterMapper) {
	// it is not good for wrap clazz in this place
	Class<?> keyFieldType = converterMapper.isPrimitive() ? Primitives
			.wrap(converterMapper.getFieldClass()) : converterMapper
			.getFieldClass();
	FieldValueConverter fieldValueConverter = defaultLocalConverterHandler
			.getLocalConverter(keyFieldType);

	if (fieldValueConverter == null) {
		throw new IllegalEntityException(clazz,
				"can find the converter for fieldType ["
						+ converterMapper.getFieldClass() + "]");
	}
	converterMapper.setFieldConverter(fieldValueConverter);

}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
private static Method findMethod( Class type, String name, Object... args ) {
    for( Method m : type.getDeclaredMethods() ) {
        if( !Objects.equals(m.getName(), name) ) {
            continue;
        }
        Class[] paramTypes = m.getParameterTypes();
        if( paramTypes.length != args.length ) {
            continue;
        }
        int matches = 0;
        for( int i = 0; i < args.length; i++ ) {
            if( paramTypes[i].isInstance(args[i]) 
                || Primitives.wrap(paramTypes[i]).isInstance(args[i]) ) {
                matches++;
            }    
        }
        if( matches == args.length ) {
            return m;
        }                
    }
    if( type.getSuperclass() != null ) {
        return findMethod(type.getSuperclass(), name, args);
    }
    return null;
}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
/**
 * Retrieves the {@link ColumnType} for specified {@link EntityColumn}.
 *
 * <p>By default, this method returns the {@link ColumnType} for the
 * {@linkplain EntityColumn column's} {@linkplain EntityColumn#getType() type}.
 *
 * <p>If the {@link ColumnType} was not found by the {@code class} of the {@link EntityColumn},
 * its superclasses are checked one by one until a {@link ColumnType} is found or until
 * the look up reaches the class representing {@link Object}.
 *
 * <p>If no {@link ColumnType} is found, an {@link IllegalStateException} is thrown.
 *
 * @param field the {@link EntityColumn} to get type conversion strategy for
 * @return the {@link ColumnType} for the given {@link EntityColumn}
 */
public C get(EntityColumn field) {
    checkNotNull(field);

    Class javaType = field.getType();
    javaType = Primitives.wrap(javaType);
    C type = null;

    while (type == null && javaType != null) {
        type = columnTypeMap.get(javaType);
        javaType = javaType.getSuperclass();
    }

    checkState(type != null,
               "Could not find storage type for %s.",
               field.getType());
    return type;
}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
private Object convertInputString(final String s, final Class<?> type) {
    if (type == String.class) {
        return s;
    } else if (type.isPrimitive() || Primitives.isWrapperType(type)) {
        final Class<?> wrapperClass = Primitives.wrap(type);
        try {
            final Method valueOf = wrapperClass.getMethod("valueOf", String.class);
            return valueOf.invoke(wrapperClass, s);
        } catch (Exception e) {
            final String message = "Failed to convert String "
                    + s + " into type " + wrapperClass
                    + ".\nCaused by: " + e;
            throw new AssertionError(message);
        }
    } else {
        final ExpressionFactory expressionFactory = expressionFactoryResolver.apply(s);
        if (expressionFactory != null) {
            final Expression expression = expressionFactory.compile(s);
            return expression.evaluate().get();
        } else {
            throw new UnsupportedOperationException("No rule implemented to convert type String to type " + type);
        }
    }
}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
private static <T> T[] doWrap(Exchanging<T> exch, Object target) {
	if (null == target) {
		return null;
	}
	
	@SuppressWarnings("unchecked")
	T[] r = newArray((Class<T>) Primitives.wrap(target.getClass().getComponentType()), Array.getLength(target));
	if (0 == r.length) {
		return r;
	}
	
	for (int i = 0; i < r.length; i++) {
		r[i] = exch.wrap(Array.get(target, i));
	}
	
	return r;
}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
private static <T> Object doUnwrap(Exchanging<T> exch, T... target) {
	if (null == target) {
		return null;
	}
	
	Class<?> clazz = Primitives.unwrap(target.getClass().getComponentType());
	Object r = Array.newInstance(clazz, target.length);
	if (0 == target.length) {
		return r;
	}
	
	T el = null;
	Object defaultVal = Defaults.defaultValue(clazz);
	for (int i = 0; i < target.length; i++) {
		Array.set(r, i, (null == (el = target[i])) ? defaultVal : exch.unwraps(el));
	}
	
	return r;
}
 

import com.google.common.primitives.Primitives; //導入依賴的package包/類
static boolean isAssignmentCompatible(Class<?> a, Class<?> b) {
	if (a == b)
		return true;

	// Wrap primitive type
	a = Primitives.wrap(a);

	// Check primitive type assignment compatibility
	if (b.isPrimitive()) {
		b = Primitives.wrap(b);

		float distance = calculateDistancePrimitive(a, b);
		return distance >= 0;

	} else {
		return b.isInstance(b);
	}
}