/*
* Copyright 2011 the original author or authors.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.jayway.jsonpath.internal;
import com.jayway.jsonpath.JsonPathException;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamClass;
import java.io.OutputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
public final class Utils {
public static final String CR = System.getProperty("line.separator");
/**
* Creates a range of integers from start (inclusive) to end (exclusive)
*
* @param start
* @param end
* @return
*/
public static List<Integer> createRange(int start, int end) {
if (end <= start) {
throw new IllegalArgumentException("Cannot create range from " + start + " to " + end + ", end must be greater than start.");
}
if (start == end-1) {
return Collections.emptyList();
}
List<Integer> range = new ArrayList<Integer>(end-start-1);
for (int i = start; i < end; i++) {
range.add(i);
}
return range;
}
// accept a collection of objects, since all objects have toString()
public static String join(String delimiter, String wrap, Iterable<? extends Object> objs) {
Iterator<? extends Object> iter = objs.iterator();
if (!iter.hasNext()) {
return "";
}
StringBuilder buffer = new StringBuilder();
buffer.append(wrap).append(iter.next()).append(wrap);
while (iter.hasNext()) {
buffer.append(delimiter).append(wrap).append(iter.next()).append(wrap);
}
return buffer.toString();
}
// accept a collection of objects, since all objects have toString()
public static String join(String delimiter, Iterable<? extends Object> objs) {
return join(delimiter, "", objs);
}
//---------------------------------------------------------
//
// IO
//
//---------------------------------------------------------
public static void closeQuietly(Closeable closeable) {
try {
if (closeable != null) {
closeable.close();
}
} catch (IOException ignore) {
}
}
//---------------------------------------------------------
//
// Strings
//
//---------------------------------------------------------
public static boolean isInt(String str) {
if (str == null) {
return false;
}
int sz = str.length();
for (int i = 0; i < sz; i++) {
if (Character.isDigit(str.charAt(i)) == false) {
return false;
}
}
return true;
}
public static boolean isNumeric(String str) {
if (str == null) {
return false;
}
int sz = str.length();
for (int i = 0; i < sz; i++) {
if (Character.isDigit(str.charAt(i)) == false && !(str.charAt(i) == '.')) {
return false;
}
}
return true;
}
/**
* <p>Checks if a CharSequence is empty ("") or null.</p>
* <p/>
* <pre>
* StringUtils.isEmpty(null) = true
* StringUtils.isEmpty("") = true
* StringUtils.isEmpty(" ") = false
* StringUtils.isEmpty("bob") = false
* StringUtils.isEmpty(" bob ") = false
* </pre>
* <p/>
* <p>NOTE: This method changed in Lang version 2.0.
* It no longer trims the CharSequence.
* That functionality is available in isBlank().</p>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if the CharSequence is empty or null
* @since 3.0 Changed signature from isEmpty(String) to isEmpty(CharSequence)
*/
public static boolean isEmpty(CharSequence cs) {
return cs == null || cs.length() == 0;
}
/**
* Used by the indexOf(CharSequence methods) as a green implementation of indexOf.
*
* @param cs the {@code CharSequence} to be processed
* @param searchChar the {@code CharSequence} to be searched for
* @param start the start index
* @return the index where the search sequence was found
*/
static int indexOf(CharSequence cs, CharSequence searchChar, int start) {
return cs.toString().indexOf(searchChar.toString(), start);
}
/**
* <p>Counts how many times the substring appears in the larger string.</p>
* <p/>
* <p>A {@code null} or empty ("") String input returns {@code 0}.</p>
* <p/>
* <pre>
* StringUtils.countMatches(null, *) = 0
* StringUtils.countMatches("", *) = 0
* StringUtils.countMatches("abba", null) = 0
* StringUtils.countMatches("abba", "") = 0
* StringUtils.countMatches("abba", "a") = 2
* StringUtils.countMatches("abba", "ab") = 1
* StringUtils.countMatches("abba", "xxx") = 0
* </pre>
*
* @param str the CharSequence to check, may be null
* @param sub the substring to count, may be null
* @return the number of occurrences, 0 if either CharSequence is {@code null}
* @since 3.0 Changed signature from countMatches(String, String) to countMatches(CharSequence, CharSequence)
*/
public static int countMatches(CharSequence str, CharSequence sub) {
if (isEmpty(str) || isEmpty(sub)) {
return 0;
}
int count = 0;
int idx = 0;
while ((idx = indexOf(str, sub, idx)) != -1) {
count++;
idx += sub.length();
}
return count;
}
//---------------------------------------------------------
//
// Validators
//
//---------------------------------------------------------
/**
* <p>Validate that the specified argument is not {@code null};
* otherwise throwing an exception with the specified message.
* <p/>
* <pre>Validate.notNull(myObject, "The object must not be null");</pre>
*
* @param <T> the object type
* @param object the object to check
* @param message the {@link String#format(String, Object...)} exception message if invalid, not null
* @param values the optional values for the formatted exception message
* @return the validated object (never {@code null} for method chaining)
* @throws NullPointerException if the object is {@code null}
*/
public static <T> T notNull(T object, String message, Object... values) {
if (object == null) {
throw new IllegalArgumentException(String.format(message, values));
}
return object;
}
/**
* <p>Validate that the argument condition is {@code true}; otherwise
* throwing an exception with the specified message. This method is useful when
* validating according to an arbitrary boolean expression, such as validating a
* primitive number or using your own custom validation expression.</p>
* <p/>
* <pre>Validate.isTrue(i > 0.0, "The value must be greater than zero: %d", i);</pre>
* <p/>
* <p>For performance reasons, the long value is passed as a separate parameter and
* appended to the exception message only in the case of an error.</p>
*
* @param expression the boolean expression to check
* @param message
* @throws IllegalArgumentException if expression is {@code false}
*/
public static void isTrue(boolean expression, String message) {
if (expression == false) {
throw new IllegalArgumentException(message);
}
}
/**
* <p>Validate that the specified argument character sequence is
* neither {@code null} nor a length of zero (no characters);
* otherwise throwing an exception with the specified message.
* <p/>
* <pre>Validate.notEmpty(myString, "The string must not be empty");</pre>
*
* @param <T> the character sequence type
* @param chars the character sequence to check, validated not null by this method
* @param message the {@link String#format(String, Object...)} exception message if invalid, not null
* @param values the optional values for the formatted exception message, null array not recommended
* @return the validated character sequence (never {@code null} method for chaining)
* @throws NullPointerException if the character sequence is {@code null}
* @throws IllegalArgumentException if the character sequence is empty
*/
public static <T extends CharSequence> T notEmpty(T chars, String message, Object... values) {
if (chars == null) {
throw new IllegalArgumentException(String.format(message, values));
}
if (chars.length() == 0) {
throw new IllegalArgumentException(String.format(message, values));
}
return chars;
}
//---------------------------------------------------------
//
// Converters
//
//---------------------------------------------------------
public static String toString(Object o) {
if (null == o) {
return null;
}
return o.toString();
}
//---------------------------------------------------------
//
// Serialization
//
//---------------------------------------------------------
/**
* <p>Serializes an {@code Object} to the specified stream.</p>
* <p/>
* <p>The stream will be closed once the object is written.
* This avoids the need for a finally clause, and maybe also exception
* handling, in the application code.</p>
* <p/>
* <p>The stream passed in is not buffered internally within this method.
* This is the responsibility of your application if desired.</p>
*
* @param obj the object to serialize to bytes, may be null
* @param outputStream the stream to write to, must not be null
* @throws IllegalArgumentException if {@code outputStream} is {@code null}
* @throws RuntimeException (runtime) if the serialization fails
*/
public static void serialize(Serializable obj, OutputStream outputStream) {
if (outputStream == null) {
throw new IllegalArgumentException("The OutputStream must not be null");
}
ObjectOutputStream out = null;
try {
// stream closed in the finally
out = new ObjectOutputStream(outputStream);
out.writeObject(obj);
} catch (IOException ex) {
throw new JsonPathException(ex);
} finally {
try {
if (out != null) {
out.close();
}
} catch (IOException ex) { // NOPMD
// ignore close exception
}
}
}
/**
* <p>Serializes an {@code Object} to a byte array for
* storage/serialization.</p>
*
* @param obj the object to serialize to bytes
* @return a byte[] with the converted Serializable
* @throws RuntimeException (runtime) if the serialization fails
*/
public static byte[] serialize(Serializable obj) {
ByteArrayOutputStream baos = new ByteArrayOutputStream(512);
serialize(obj, baos);
return baos.toByteArray();
}
// Deserialize
//-----------------------------------------------------------------------
/**
* <p>Deserializes an {@code Object} from the specified stream.</p>
* <p/>
* <p>The stream will be closed once the object is written. This
* avoids the need for a finally clause, and maybe also exception
* handling, in the application code.</p>
* <p/>
* <p>The stream passed in is not buffered internally within this method.
* This is the responsibility of your application if desired.</p>
*
* @param inputStream the serialized object input stream, must not be null
* @return the deserialized object
* @throws IllegalArgumentException if {@code inputStream} is {@code null}
* @throws RuntimeException (runtime) if the serialization fails
*/
public static Object deserialize(InputStream inputStream) {
if (inputStream == null) {
throw new IllegalArgumentException("The InputStream must not be null");
}
ObjectInputStream in = null;
try {
// stream closed in the finally
in = new ObjectInputStream(inputStream);
return in.readObject();
} catch (ClassNotFoundException ex) {
throw new JsonPathException(ex);
} catch (IOException ex) {
throw new JsonPathException(ex);
} finally {
try {
if (in != null) {
in.close();
}
} catch (IOException ex) { // NOPMD
// ignore close exception
}
}
}
/**
* <p>Deserializes a single {@code Object} from an array of bytes.</p>
*
* @param objectData the serialized object, must not be null
* @return the deserialized object
* @throws IllegalArgumentException if {@code objectData} is {@code null}
* @throws RuntimeException (runtime) if the serialization fails
*/
public static Object deserialize(byte[] objectData) {
if (objectData == null) {
throw new IllegalArgumentException("The byte[] must not be null");
}
ByteArrayInputStream bais = new ByteArrayInputStream(objectData);
return deserialize(bais);
}
/**
* <p>Custom specialization of the standard JDK {@link java.io.ObjectInputStream}
* that uses a custom <code>ClassLoader</code> to resolve a class.
* If the specified <code>ClassLoader</code> is not able to resolve the class,
* the context classloader of the current thread will be used.
* This way, the standard deserialization work also in web-application
* containers and application servers, no matter in which of the
* <code>ClassLoader</code> the particular class that encapsulates
* serialization/deserialization lives. </p>
* <p/>
* <p>For more in-depth information about the problem for which this
* class here is a workaround, see the JIRA issue LANG-626. </p>
*/
static class ClassLoaderAwareObjectInputStream extends ObjectInputStream {
private ClassLoader classLoader;
/**
* Constructor.
*
* @param in The <code>InputStream</code>.
* @param classLoader classloader to use
* @throws IOException if an I/O error occurs while reading stream header.
* @see java.io.ObjectInputStream
*/
public ClassLoaderAwareObjectInputStream(InputStream in, ClassLoader classLoader) throws IOException {
super(in);
this.classLoader = classLoader;
}
/**
* Overriden version that uses the parametrized <code>ClassLoader</code> or the <code>ClassLoader</code>
* of the current <code>Thread</code> to resolve the class.
*
* @param desc An instance of class <code>ObjectStreamClass</code>.
* @return A <code>Class</code> object corresponding to <code>desc</code>.
* @throws IOException Any of the usual Input/Output exceptions.
* @throws ClassNotFoundException If class of a serialized object cannot be found.
*/
@Override
protected Class<?> resolveClass(ObjectStreamClass desc) throws IOException, ClassNotFoundException {
String name = desc.getName();
try {
return Class.forName(name, false, classLoader);
} catch (ClassNotFoundException ex) {
return Class.forName(name, false, Thread.currentThread().getContextClassLoader());
}
}
}
private Utils () {}
}