thecodemechanic

How to check empty NSString

Checking empty string

NSString *string1=@"";
NSString *string2=@" ";
NSString *string3=@" \n ";

string1 is an empty string.

string2 is not empty having empty whitespace

[[string2 stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];

string3 is not empty having empty whitespace and new line character

[string3 stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

all the above string can be checked with @"" to test empty string.

how to create singleton object

Singleton object are created only once in the life cycle of the app.

Singleton object can be accessed using [ClassName sharedInstance].

+(id)sharedInstance{
static MyClassManager *sharedMyClassManager = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedMyClassManager = [[self alloc] init];
});
retrun sharedMyClassManager;
}

WebRep

currentVote

noRating

noWeight

@property types

Objects have properties to access for public.
Types of attributes

atomic - can be accessed only by one thread at a time.
non-atomic - can be accessed by any number of threads.
readonly - having access for readonly for object.
readwrite - having access for read and write object.
retain - will increase the retain count of the object. This is called as shallow copy. This will not create new memory reference.

copy - will create new memory location and copy all data to the newly created object. This is called as Deep copy.
assign - This will neither create new reference nor increase the retain count of the object. All delegate properties are assign.

How to install xcode

Download Xcode from https://developer.apple.com/xcode/

Drag and drop to applications.

Then open Xcode from Applications.

StringArray to String in java

By Using StringUtils.join method in apache common we can easily convert String[] to String.
You can download this jar from Here.

package commonsUtils;
import org.apache.commons.lang.StringUtils;
public class SampleRunnable {
public static void main(String[] args) {
// TODO Auto-generated method stub
String[] stringArray = { "one", "two", "three", "four", "five" };
String finalString = StringUtils.join(stringArray,","); //Output comma(,) seperated string
String finalString2 = StringUtils.join(stringArray,":"); //Output colon(,) seperated string
System.out.println(" finalString :: "+finalString);
System.out.println(" finalString2 :: "+finalString2);
}
}

Output :

finalString :: one,two,three,four,five

finalString2 :: one:two:three:four:five

Format Date in java

DateFormatUtils.format Utility method is used to format date from date to string.
You can use this method with the help of commons-lang-2.6.jar.
You can download this jar from Here.

package commonsUtils;
import java.util.Date;
import org.apache.commons.lang.time.DateFormatUtils;
public class SampleRunnable {
public static void main(String[] args) {
// TODO Auto-generated method stub
Date today = new Date();
String firstPattern = DateFormatUtils.format(today,"MM/dd/yyyy HH:mm:ss");
System.out.println("Date to String in MM/dd/yyyy HH:mm:ss::"+firstPattern);
String secondPattern = DateFormatUtils.format(today,"dd/MM/yyyy HH:mm:ss");
System.out.println("Date to String in dd/MM/yyyy HH:mm:ss::"+secondPattern);
String thirdPattern = DateFormatUtils.format(today,"MM/dd/yyyy");
System.out.println("Date to String in MM/dd/yyyy::"+thirdPattern);
String fourthPattern = DateFormatUtils.format(today,"dd/MM/yyyy");
System.out.println("Date to String in dd/MM/yyyy::"+fourthPattern);
}
}

Output :

Date to String in MM/dd/yyyy HH:mm:ss::07/17/2013 15:06:30
Date to String in dd/MM/yyyy HH:mm:ss::17/07/2013 15:06:30
Date to String in MM/dd/yyyy::07/17/2013
Date to String in dd/MM/yyyy::17/07/2013

File.separator vs File.pathSeparator

File.separator == > separator: Platform dependent default name-separator character as String. For windows, it’s ‘\’ and for unix it’s ‘/’.
File.separatorChar ==>separatorChar: Same as separator but it’s char.
File.pathSeparator ==> pathSeparator: Platform dependent variable for path-separator. For example PATH or CLASSPATH variable list of paths separated by ‘:’ in Unix systems and ‘;’ in Windows system.
File.pathSeparatorChar ==> pathSeparatorChar: Same as pathSeparator but it’s char.
This is the environment independent property.This will be usefull for file upload and downloading etc.

package commonsUtils;
import java.io.File;
public class FileSep{
public static void main(String[] args){
String filepath = File.separator + "sample" + File.separatorChar + "seperator";
String pathSep = File.pathSeparator + "sample" + File.pathSeparatorChar + "seperator";
System.out.println("The path of the file is : " + filepath);
System.out.println("The path of the file is : " + pathSep);
System.out.println("File.separator = "+File.separator)
System.out.println("File.separatorChar = "+File.separatorChar);
System.out.println("File.pathSeparator = "+File.pathSeparator);
System.out.println("File.pathSeparatorChar = "+File.pathSeparatorChar);
}
}

Output :

For Windows

-------------

The path of the file is : \sample\seperator

The path of the file is : ;sample;seperator

File.separator = \

File.separatorChar = \

File.pathSeparator = ;

File.pathSeparatorChar = ;

For Unix

----------

The path of the file is : /sample/seperator

The path of the file is : :sample:seperator

File.separator = /

File.separatorChar = /

File.pathSeparator = :

File.pathSeparatorChar = :

Remove null values in ArrayList

By Using Collections.singleton(null) we can remove the null values in the list.

package commonsUtils;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
public class RemDupList {
public static void main(String[] args) {
// TODO Auto-generated method stub
List<String> arrayList1 = new ArrayList<String>();
arrayList1.add("A");
arrayList1.add("A");
arrayList1.add("B");
arrayList1.add("B");
arrayList1.add("B");
arrayList1.add("C");
arrayList1.add(null);
arrayList1.add(null);
for (String item : arrayList1){
System.out.println(item);
}
HashSet<String> hashSet = new HashSet<String>(arrayList1);
arrayList1 = new ArrayList<String>(hashSet);
System.out.println(" =============== ");
arrayList1 .removeAll(Collections.singleton(null)); //This will remove the null values
arrayList1 .removeAll(Collections.singleton("A")); //This will remove the value "A" in the entire list.
for (String item : arrayList1 ){
System.out.println(item);
}
}
}

Output :

Before Removing null values

null

===============

After Removing null values

StringEscapeUtils.escapeXml

Unescapes a string containing XML entity escapes to a string containing the actual Unicode characters corresponding to the escapes.
Supports only the five basic XML entities (gt, lt, quot, amp, apos). Does not support DTDs or external entities.
Note that numerical \\u unicode codes are unescaped to their respective unicode characters. This may change in future releases.

package com.utilitySample;
import org.apache.commons.lang.StringUtils;
public class StringUtility {
public static void main(String[] args) {
String xmlString = "<data>";
System.out.println("After escapeXml::"+StringEscapeUtils.escapeXml(xmlString));
System.out.println("After unescapeXml::"+StringEscapeUtils.unescapeXml(xmlString));
}
}

Output :

After escapeXml::<data>
After unescapeXml::<data>

StringEscapeUtils.escapeSql

Escapes the characters in a String to be suitable to pass to an SQL query.

For example,


statement.executeQuery("SELECT * FROM MOVIES WHERE TITLE='" + 

StringEscapeUtils.escapeSql("McHale's Navy") + "'");

At present, this method only turns single-quotes into doubled single-quotes ("McHale's Navy" => "McHale''s Navy"). It does not handle the cases of percent (%) or underscore (_) for use in LIKE clauses.

package com.utilitySample;
import org.apache.commons.lang.StringUtils;
public class StringUtility {
public static void main(String[] args) {
String unescapedSql = "L'OREAL";
System.out.println("After escapeSql::"+StringEscapeUtils.escapeSql(unescapedSql));
System.out.println(unescapedSql);
}
}

Output :

After escapeSql::L''OREAL
L'OREAL

StringEscapeUtils.escapeJavaScript

Escapes the characters in a String using JavaScript String rules.
Escapes any values it finds into their JavaScript String form. Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.)
So a tab becomes the characters '\\' and 't'.
The only difference between Java strings and JavaScript strings is that in JavaScript, a single quote must be escaped.

package com.utilitySample;
import org.apache.commons.lang.StringUtils;
public class StringUtility {
public static void main(String[] args) {
String inputString = "What's i\tn a name?";
System.out.println("After escapeJavaScript::"+StringEscapeUtils.escapeJavaScript(inputString));
System.out.println("After unescapeJavaScript::"+StringEscapeUtils.unescapeJavaScript(inputString));
}
}

Output :

After escapeJavaScript::What\'s i\tn a name?
After unescapeJavaScript::What's i n a name?

StringEscapeUtils.escapeJava

Escapes the characters in a String using Java String rules
Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.)
So a tab becomes the characters '\\' and 't'.
The only difference between Java strings and JavaScript strings is that in JavaScript, a single quote must be escaped.

package com.utilitySample;
import org.apache.commons.lang.StringUtils;
public class StringUtility {
public static void main(String[] args) {
String inputStr = "sample jav\ta escape";
System.err.println("After escape ::"+StringEscapeUtils.escapeJava(inputStr));
System.err.println("After unescape ::"+StringEscapeUtils.unescapeJava(inputStr));
}
}

Output :

After escape ::sample jav\ta escape
After unescape ::sample jav a escape

How to Unlock XELSYSADM account in OIM

If Xelsysadm account gets locked in OIM ther are 2 ways to unlock it.

If you have any other adminstrator account, login using that acount and unlock the user.
Update the usr table to unlock the xelsysadm account using below commands.

update usr set usr_login_attempts_ctr=0 where usr_login=’XELSYSADM’;
update usr set usr_locked=0 where usr_login=’XELSYSADM’;
Commit;

Remove Duplicate in UserDefinied list

we can remove duplicate object in user definied list by overriding equals and hashcode method in java.
first create Java Bean.

Person.java
-------------

package com.utilitySample;
public class Person{
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
/**
* we have to override equals method to avaoid duplicates in userDefined list.
*/
public boolean equals(Object obj) {
boolean result = false;
Person person = (Person) obj;
if (this.getName().equalsIgnoreCase(person.getName())){
result = true;
}
return result;
}
public int hashCode() {
// TODO Auto-generated method stub
return 1;
}
}

Then create your main java class.

RemDupList.java
------------------

package com.utilitySample;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
public class RemDupList {
public static void main(String[] args) {
List<Person> personList = new ArrayList<Person>();
Person person = new Person();
person.setName("amazon");
personList.add(person);
person = new Person();
person.setName("amazon");
personList.add(person);
person = new Person();
person.setName("stalin");
personList.add(person);
person = new Person();
person.setName("stalin");
personList.add(person);
for (Person pers:personList){
System.out.println("Before removing duplicates ::"+pers.getName());
}
Set<Person> personSet = new HashSet<Person>(personList);
for (Person pers:personSet){
System.out.println("After removing duplicates ::"+pers.getName());
}
List<Person> personList2 = new ArrayList<Person>();
personList2.addAll(personSet);
System.out.println("size ::"+personList2.size());
for (int i = 0; i < personList2.size(); i++) {
System.out.println("value ::"+personList2.get(i).getName());
}
}
}

Output :

Before removing duplicates ::amazon
Before removing duplicates ::amazon
Before removing duplicates ::stalin
Before removing duplicates ::stalin
After removing duplicates ::stalin
After removing duplicates ::amazon
size ::2
value ::stalin
value ::amazon

Remove Duplicates in list

We have to create a list of String.
Then pass that string top Hashset.(i.e)HashSet will not allow duplicates.
So the resultant list is a unique list.
The same procedure you have to follow for Interger etc.For user definied list we have to override
hashCode and Equals method.That you can see in my next post.

package com.utilitySample;
import org.apache.commons.lang.StringUtils;
public class RemoveDuplicate {
public static void main(String[] args) {
List<String> arrayList1 = new ArrayList<String>();
arrayList1.add("vel");
arrayList1.add("vel");
arrayList1.add("dinesh");
arrayList1.add("dinesh");
arrayList1.add("dinesh");
arrayList1.add("prasanth");
List<String> arrayList2 = new ArrayList<String>(new HashSet<String>(arrayList1));
for (String item : arrayList2){
System.out.println(item);
}
}
}

Output :

dinesh
vel
prasanth

Pages