#Java - Code Snippets for '#Java.lang' - 24 code snippet(s) found |
|
Sample 1. Write a Program to reverse a string iteratively and recursively | |
|
Using String method -
new StringBuffer(str).reverse().toString();
Iterative -
Strategy - Loop through each character of a String from last to first and append the character to StringBuilder / StringBuffer
public static String getReverseString(String str){
StringBuffer strBuffer = new StringBuffer(str.length);
for(int counter=str.length -1 ; counter>=0;counter--){
strBuffer.append(str.charAt(counter));
}
return strBuffer;
}
Recursive -
Strategy - Call the method with substring starting from 2nd character recursively till we have just 1 character.
public static String getReverseString(String str){
if(str.length <= 1){
return str;
}
return (getReverseString(str.subString(1)) + str.charAt(0);
}
|
|
Like Feedback string StringBuffer recursion for loop control statements loop statement stringbuffer.append java.lang.String java.lang.StringBuffer String Manipulation |
|
|
Sample 2. Switch Case with Enum | | Admin info@buggybread.com |
|
|
public enum State {
NEVADA, CALIFORNIA, WASHINGTON;
}
public static void method(States stateName) {
switch (stateName) {
case NEVADA:
System.out.println("You are in Nevada");
break;
case CALIFORNIA:
System.out.println("You are in California");
break;
case WASHINGTON:
System.out.println("You are in Washington");
break;
}
}
|
|
Like Feedback switch case switch case enum switch with enums switch and enums |
|
|
Sample 3. Blogger API for creating Posts ( Change xxxxxx to your blog specific info ) | |
|
package Reader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import com.squareup.okhttp.MediaType;
import com.squareup.okhttp.OkHttpClient;
public class BlogPostCreater {
public static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");
OkHttpClient client = new OkHttpClient();
String post(String title, String content,String label,String authorization_key) throws IOException {
content = content.replace(""",""");
String url = "https://www.googleapis.com/blogger/v3/blogs/xxxxxxxxxx/posts?clientId=xxxxxxxx&clientSecret=xxxxxxxx";
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(url);
// add header
post.setHeader("Authorization", authorization_key);
post.setHeader("Content-type","application/json");
post.setEntity(new StringEntity(buildJson(title,content,label)));
HttpResponse response = client.execute(post);
System.out.println(response);
return "true";
}
String buildJson(String title, String content,String label) {
System.out.println(label);
return "{"status": "LIVE", "content": ""+content+"", "kind": "blogger#post"" +
", "title": ""+title+"", "url": "xxxxxx", " +
""readerComments": "DONT_ALLOW_HIDE_EXISTING", "author": {" +
""url": "https://www.blogger.com/profile/04326686331881561093", " +
""image": {" +
""url": "//lh4.googleusercontent.com/-64Ucx9lX9Q4/AAAAAAAAAAI/AAAAAAAAAx0/-rUjBgS3djE/s35-c/photo.jpg"" +
"}, " +
""displayName": "Vivek Vermani", " +
""id": "g108356395081185480077"" +
"}, "updated": "2015-09-28T09:46:12+05:30", "replies": {"totalItems": "0", " +
""selfLink": "https://www.googleapis.com/blogger/v3/blogs/xxxxxxxxxx/posts/2495464003469367152/comments"" +
"}, "blog": {"id": "4275342475651800664"}, " +
""etag": "'GtyIIQmNmmUjEA0nwhSqMElCJ1g/dGltZXN0YW1wOiAxNDQzNDEzNzcyMDc1Cm9mZnNldDogMTk4MDAwMDAK'", " +
""published": "2015-09-28T09:46:00+05:30", " +
""id": "2495464003469367152", " +
""selfLink": "https://www.googleapis.com/blogger/v3/blogs/xxxxxx/posts/2495464003469367152"}";
}
public String post(String url, Map<String,String> formParameters) throws ClientProtocolException, IOException {
HttpPost request = new HttpPost(url);
List <NameValuePair> nvps = new ArrayList <NameValuePair>();
for (String key : formParameters.keySet()) {
nvps.add(new BasicNameValuePair(key, formParameters.get(key)));
}
request.setEntity(new UrlEncodedFormEntity(nvps));
return execute(request);
}
// makes request and checks response code for 200
private String execute(HttpRequestBase request) throws ClientProtocolException, IOException {
HttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(request);
HttpEntity entity = response.getEntity();
String body = EntityUtils.toString(entity);
if (response.getStatusLine().getStatusCode() != 200) {
throw new RuntimeException("Expected 200 but got " + response.getStatusLine().getStatusCode() + ", with body " + body);
}
return body;
}
}
|
|
Like Feedback blogger api blogger api for post creation java.lang.RuntimeException |
|
|
Sample 4. Interface Default Methods ( Base Class Definition has precedence over Interface Default Method if both are being extended and implemented and have common method definition ) | |
|
HelloJava8Base
public class HelloJava8Base {
public void defaultMethod() {
System.out.println("Default Method Base Class Implementation");
}
}
DefaultMethodInterface
public interface DefaultMethodInterface {
default public void defaultMethod() {
System.out.println("Default Method Interface Implementation");
}
}
HelloJava8
public class HelloJava8 extends HelloJava8Base implements DefaultMethodInterface,DefaultMethodInterface2 {
public static void main(String[] args){
DefaultMethodInterface dmi = new HelloJava8();
dmi.defaultMethod(); // Prints "Default Method Base Class Implementation"
}
}
|
|
Like Feedback interface default methods java 8 interfaces |
|
|
|
Sample 5. Scheduling task using java.util.timer | |
|
static {
timer.schedule(new ScheduledTask(), 60000, 60000);
}
private static class Schedule extends TimerTask {
@Override public void run() {
//doSomething();
}
}
|
|
Like Feedback java.util.timer java.util.TimerTask scheduling task java.lang Override |
|
|
Sample 6. Code Sample / Example / Snippet of java.lang.reflect.Field | |
|
public Object getDeclaredField(Class targetClass, String name, Object target)
throws Exception
{
if (System.getSecurityManager() != null)
{
Actions actions = (Actions) m_actions.get();
actions.set(Actions.GET_FIELD_ACTION, targetClass, name, target);
try
{
return AccessController.doPrivileged(actions, m_acc);
}
catch (PrivilegedActionException e)
{
throw e.getException();
}
}
else
{
Field field = targetClass.getDeclaredField(name);
field.setAccessible(true);
return field.get(target);
}
}
|
|
Like Feedback java.lang.reflect.Field |
|
|
Sample 7. Method to check if input String is Palindrome | |
|
private static boolean isPalindrome(String str) {
if (str == null)
return false;
StringBuilder strBuilder = new StringBuilder(str);
strBuilder.reverse();
return strBuilder.toString().equals(str);
}
|
|
Like Feedback Palindrome strBuilder.reverse string stringbuilder.reverse java.lang.StringBuilder |
|
|
Sample 8. Get the Maximum of two numbers | |
|
int maxNumber = Math.max(100, 500);
System.out.println(maxNumber);
|
|
Like Feedback maximum of two numbers Math.max |
|
|
Sample 9. Parse JSON using JSONParser | |
|
JSONParser jsonParser = new JSONParser();
String jsonMessage = JSONMessageAsString;
JSONObject jsonObject = null;
try {
jsonObject = (JSONObject) jsonParser.parse(jsonMessage);
} catch (ParseException e) {
System.out.println("Error in Parsing JSON");
}
Long id = (Long) jsonObject.get("Id");
String name = (String) jsonObject.get("Name");
|
|
Like Feedback JSON Parsing JSON Parser |
|
|
|
Sample 10. Clear Map entries after expiration time using Apache commons PassiveExpiringMap | |
|
PassiveExpiringMap<String,String> cache = new PassiveExpiringMap<String,String>(1,TimeUnit.SECONDS); // Expiration time of 1 sec
cache.put("Key1", "Value1");
System.out.println(cache.containsKey("Key1")); // prints true
Thread.sleep(1000);
System.out.println(cache.containsKey("Key1")); // prints false
|
|
Like Feedback Clear Map entries after expiration PassiveExpiringMap map apache commons TimeUnit.SECONDS Thread.sleep |
|
|
Sample 11. Make a map readonly using Apache Commons UnmodifiableMap | |
|
Map<String,String> map = new HashMap();
map.put("Key1", "Value1");
Map<String,String> unmodifiableMap = UnmodifiableMap.unmodifiableMap(map);
unmodifiableMap.put("Key2", "Value2"); // throws java.lang.UnsupportedOperationException
|
|
Like Feedback readonly map apache commons |
|
|
Sample 12. Make a Map entry read only using Apache Commons UnmodifiableMapEntry | |
|
Entry entry = new UnmodifiableMapEntry("Key2", "Value2");
entry.setValue("Value3"); // throws java.lang.UnsupportedOperationException
|
|
Like Feedback read only map entry UnmodifiableMapEntry Apache commons collections |
|
|
Sample 13. Get the properties of class (i.e package name , interfaces , subclasses etc ) using ClassUtils( Apache Commons ) | |
|
Class class1 = ClassUtils.getClass("BuggyBreadTest");
System.out.println(ClassUtils.getPackageName(class1));
System.out.println(ClassUtils.getAllInterfaces(class1));
|
|
Like Feedback ClassUtils Apache Commons Get Class Properties java.lang.Class |
|
|
Sample 14. Create an UnmodifiableMultiSet ( Read only set allowing multiple values ) using Apache Commons | |
|
MultiSet<String> multiSet = new HashMultiSet();
multiSet.add("Albama");
multiSet.add("Albama");
multiSet.add("Albama");
System.out.println(multiSet); // Prints [Albama:3]
UnmodifiableMultiSet<String> unmodifiablemultiSet = (UnmodifiableMultiSet<String>) MultiSetUtils.unmodifiableMultiSet(multiSet);
unmodifiablemultiSet.add("Albama"); // throws java.lang.UnsupportedOperationException
|
|
Like Feedback UnmodifiableMultiSet Apache Commons Collections Set MultiSet |
|
|
|
Sample 15. Usage of java.lang.reflect.Field; | |
|
Form form1 = resources.getForm("fr", "", "", "testForm1_fr");
Field field1 = form1.getField("testProperty1");
|
|
Like Feedback Reflection java.lang.reflect.Field |
|
|
Sample 16. Usage of java.lang.reflect.Modifier | |
|
Field f = DomainValidator.class.getDeclaredField(arrayName);
final boolean isPrivate = Modifier.isPrivate(f.getModifiers());
if (isPrivate) {
f.setAccessible(true);
}
|
|
Like Feedback Reflection java.lang.reflect.Modifier |
|
|
Sample 17. Usage of org.apache.commons.validator.ValidatorAction | |
|
ValidatorAction va = new ValidatorAction();
va.setName(action);
va.setClassname("org.apache.commons.validator.ValidatorTest");
va.setMethod("formatDate");
va.setMethodParams("java.lang.Object,org.apache.commons.validator.Field");
FormSet fs = new FormSet();
Form form = new Form();
form.setName("testForm");
Field field = new Field();
field.setProperty(property);
field.setDepends(action);
form.addField(field);
fs.addForm(form);
resources.addValidatorAction(va);
resources.addFormSet(fs);
|
|
Like Feedback Apache Commons ValidatorAction FormSet |
|
|
Sample 18. Usage of java.lang.reflect.ParameterizedType | |
|
ParameterizedType ptype = (ParameterizedType)type;
Class raw = (Class)ptype.getRawType();
|
|
Like Feedback Reflection ParameterizedType |
|
|
Sample 19. Code Sample / Example / Snippet of java.lang.reflect.Type | |
|
public static Type stripGenerics(Type type) {
if (type instanceof GenericArrayType) {
final Type componentType =
((GenericArrayType) type).getGenericComponentType();
return new ArrayType(stripGenerics(componentType));
} else if (type instanceof ParameterizedType) {
return ((ParameterizedType) type).getRawType();
} else {
return type;
}
}
|
|
Like Feedback java.lang.reflect.Type |
|
|
|
Sample 20. Mark a method as deprecated | |
|
@Deprecated
public Employee getEmployee(int employeeId){
}
|
|
Like Feedback deprecate deprecated annotation |
|
|
Sample 21. Code Sample / Example / Snippet of java.lang.reflect.Method | |
|
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
try {
Method bridge = handler.getClass().getMethod(method.getName(), method.getParameterTypes());
bridge.setAccessible(true);
return bridge.invoke(handler, args);
}
catch (NoSuchMethodException ex) {
return super.invoke(proxy, method, args);
}
catch (InvocationTargetException ex) {
throw ex.getCause();
}
}
|
|
Like Feedback java.lang.reflect.Method |
|
|
Sample 22. Code Sample / Example / Snippet of org.apache.bcel.generic.ClassElementValueGen | |
|
public void testCreateClassElementValue() throws Exception
{
final ClassGen cg = createClassGen("HelloWorld");
final ConstantPoolGen cp = cg.getConstantPool();
final ObjectType classType = new ObjectType("java.lang.Integer");
final ClassElementValueGen evg = new ClassElementValueGen(classType, cp);
assertTrue("Unexpected value for contained class: '"
+ evg.getClassString() + "'", evg.getClassString().contains("Integer"));
checkSerialize(evg, cp);
}
|
|
Like Feedback org.apache.bcel.generic.ClassElementValueGen |
|
|
Sample 23. Code Sample / Example / Snippet of org.apache.bcel.classfile.ConstantCP | |
|
public String getClassName( final ConstantPoolGen cpg ) {
final ConstantPool cp = cpg.getConstantPool();
final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
final String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
if (className.startsWith("[")) {
return "java.lang.Object";
}
return className.replace('/', '.');
}
|
|
Like Feedback org.apache.bcel.classfile.ConstantCP |
|
|
Sample 24. Usage of java.lang.module.ModuleReference , java.lang.module.ModuleDescriptor and java.lang.module.ResolvedModule; | |
|
for (ResolvedModule resolvedModule : cf.modules()) {
ModuleReference mref = resolvedModule.reference();
ModuleDescriptor descriptor = mref.descriptor();
String name = descriptor.name();
URI uri = mref.location().orElse(null);
ClassLoader loader = moduleToLoader.get(resolvedModule.name());
Module m;
if (loader == null && name.equals("java.base")) {
// java.base is already defined to the VM
m = Object.class.getModule();
} else {
m = new Module(layer, loader, descriptor, uri);
}
nameToModule.put(name, m);
moduleToLoader.put(name, loader);
}
|
|
Like Feedback |
|
|