Path Set For Java And Javac (Java Compiler ). If You Save Java Source File In Jdk/Bin Directory Then No Need Path Setup But If You Save Another Directory Then You Need To Path VAriable Set In This Way For Permanent Path .
MyComputer properties -> advanced tab -> environment variables -> new tab of user variable -> write path in variable name -> write path of bin folder in variable value -> ok -> ok -> ok
1) Go to MyComputer properties
2) Click on the advanced tab
3) Click on environment variables
4) Click on the new tab of user variables
5) Write the path in the variable name
6) Copy the path of bin folder
8) Click on ok button
9) Click on ok button
Now your permanent path is set. You can now execute any program of java from any drive.
1 Open Eclipse With Your Eclipse WorkSpace
2. File -> New -> Java Project ->Project Name (Example Name As Student )And Next And Finish
3. Create Java Class And Fill Source Folder Student/src. Package Name Your Choice Example student.name.And Class Name example Student.ok
4 Implement Main Method And Main Function For Output.
emailEditText = (EditText) findViewById(R.id.editText_email);
passEditText = (EditText) findViewById(R.id.editText_password);
//Perform when need;
final String email = emailEditText.getText().toString();
if (!isValidEmail(email)) {emailEditText.setError("Invalid Email");}
final String pass = passEditText.getText().toString();
if (!isValidPassword(pass)) {passEditText.setError("Invalid Password");}
initilize method after oncreate block
// validating email id
private boolean isValidEmail(String email) {
String EMAIL_PATTERN = "^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@"+ "[A-Za-z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";
Pattern pattern = Pattern.compile(EMAIL_PATTERN);
Matcher matcher = pattern.matcher(email);
return matcher.matches();
}
// validating password with retype password
private boolean isValidPassword(String pass) {
if (pass != null && pass.length() > 6) {
return true;
}
return false;
}
Email & Password Validation
android-check-empty-edittext
input = (EditText) findViewById(R.id.editText1);
if(input.getText().toString().equals(""))
{
Toast.makeText(MainActivity.this, "Input Text Is Empty.. Please Enter Some Text", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(MainActivity.this, "Input Text is Not Empty", Toast.LENGTH_SHORT).show();
}
GetEditText = edittext.getText().toString();
if(TextUtils.isEmpty(GetEditText)){
Toast.makeText(MainActivity.this, "EditText is Empty", Toast.LENGTH_LONG).show();
}
else {
Toast.makeText(MainActivity.this, "EditText is Not Empty", Toast.LENGTH_LONG).show();
}
Recycler view is a more advanced version of listview and works based on View holder design pattern. Using recyclerview we can show grids as well as a list of items.
This example demonstrates how to integrate RecyclerView by creating a beautiful student records app that displays student name with age.
Step 1 â Create a new project in Android Studio, go to File â New Project and fill all required details to create a new project.
Step 2 â Open build.gradle and add Recycler view library dependency.
In the above code, we have added a recycler view and studentAdapter. In that student adapter, we have passed studentDatalist as ArrayList. In Student, data list contains the name of the student and age.
Step 5 â Following is the content of the modified file src/ StudentAdapter.java.
package com.example.andy.tutorialspoint;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.List;
class StudentAdapter extends RecyclerView.Adapter {
List studentDataList;
public StudentAdapter(List studentDataList) {
this.studentDataList=studentDataList;
}
@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View itemView = LayoutInflater.from(viewGroup.getContext())
.inflate(R.layout.student_list_row, viewGroup, false);
return new MyViewHolder(itemView);
}
@Override
public void onBindViewHolder(MyViewHolder viewHolder, int i) {
studentData data=studentDataList.get(i);
viewHolder.name.setText(data.name);
viewHolder.age.setText(String.valueOf(data.age));
}
@Override
public int getItemCount() {
return studentDataList.size();
}
class MyViewHolder extends RecyclerView.ViewHolder {
TextView name,age;
public MyViewHolder(View itemView) {
super(itemView);
name=itemView.findViewById(R.id.name);
age=itemView.findViewById(R.id.age);
}
}
}
In the adapter class, we have four methods as shown below –
onCreateViewHolder() – It is used to create a view holder and it returns a view.
onBindViewHolder() – it going to bind with created view holder.
getItemCount() – it contains size of list.
MyViewHolder class– it is view holder inner class which is extended by RecyclerView.ViewHolder
Step 6 â Following is the modified content of the xml res/layout/student_list_row.xml.
In the above list item view, we have created two text views for name and age.
Step 7 â Following is the content of the modified file src/ studentData.java.
package com.example.andy.tutorialspoint;
class studentData {
String name;
int age;
public studentData(String name, int age) {
this.name=name;
this.age=age;
}
}
In the above code informs about student data object. Let’s try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from the android studio, open one of your project’s activity files and click Run icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen â
OLEETECH 