The employee ingest system for Java projects

In Java SE, the operation of IO streams and collections is important in the application. Next, I demonstrate the use of knowledge points such as IO streams and collections in practice in the form of a small project.

The project is named "Employee ingest system" and operates on the eclipse's console. The operating interface is as follows:

The file structure of the project is as follows:

Step 1:

The code for the Ingress class Systemmain is:

Package Empsystem;

Import Java.util.Scanner;

/**
* Main interface
* One scanner Entry object
* Employ class
* File path
* Check the weight searchid
* @author Li Zhangyong
*
*/

Public class Systemmain {
Private Scanner sc=new Scanner (system.in);

Public Systemmain () {
Showwelcome ();
}

public void Showwelcome () {
System.out.println ("----Employee ingest system");
System.out.println ("1. Adding staff functions");
System.out.println ("2. View employee Functions");
System.out.println ("3. Modify employee Functions");
System.out.println ("4. Remove employee Features");
System.out.println ("5. Exit system");
String choice=sc.nextline ();
Switch (choice) {
Case "1":
System.out.println ("You have selected to add user functionality");
Add
New Add ();
Break
Case "2":
System.out.println ("You have selected to view user features");
Search
New Showemp ();
Break
Case "3":
System.out.println ("You have selected to modify user features");
Modify
New Modify ();
Break
Case "4":
System.out.println ("You have selected to remove user features");
Delete user Delete
new delete ();
Break
Case "5":
System.out.println ("You have selected to exit the system");
Return
Default:
System.out.println ("No this feature");
Break
}
Showwelcome ();


}

public static void Main (string[] args) {
new Systemmain ();

}

}

Step 2:

Write file path filepath interface.

Package Empsystem;

Public interface FilePath {
public static final String path_name= "Emp.em";
}

Step 3:

Write employee class employ.

Package Empsystem;

Import java.io.Serializable;

/**
* Id,name
* @author Li Zhangyong
*
*/
Public class employ implements serializable{
private int id;
private String name;

Public employ () {

}

public employ (int ID, String name) {
Super ();
This.id = ID;
THIS.name = name;
}

public int getId () {
return ID;
}

public void setId (int id) {
This.id = ID;
}

Public String GetName () {
return name;
}

public void SetName (String name) {
THIS.name = name;
}

@Override
Public String toString () {
Return "employ [id=" + ID + ", name=" + name + "]\n";
}
}

Step 4:

Find the class Searchid of the employee based on the ID.

Package Empsystem;

Import Java.io.File;
Import Java.io.FileInputStream;
Import java.io.FileNotFoundException;
Import java.io.IOException;
Import Java.io.ObjectInputStream;
Import java.util.ArrayList;
Import java.util.List;

/**
* Find employees by ID
* @author Li Zhangyong
*
*/
public class Searchid {
Private Searchid () {}

public static employ Searchid (int id) {
File File=new file (filepath.path_name);
if (file.exists ()) {
try {
ObjectInputStream ois=new ObjectInputStream (new FileInputStream (file));
try {
Arraylist<employ> ems= (arraylist<employ>) ois.readobject ();
Ois.close ();
for (int i=0;i<ems.size (); i++) {
if (Id==ems.get (i). GetId ()) {
return Ems.get (i);
}
}

} catch (ClassNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}

} catch (FileNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
} catch (IOException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}

}else{
return null;
}

return null;
}
}

Step 5:

Next is to increase, check, change, delete the class, respectively, is the Add class, Showemp class, modify class, modify class.

(1)

Package Empsystem;

Import Java.io.File;
Import Java.io.FileInputStream;
Import java.io.FileNotFoundException;
Import Java.io.FileOutputStream;
Import java.io.IOException;
Import Java.io.ObjectInputStream;
Import Java.io.ObjectOutputStream;
Import java.util.ArrayList;
Import Java.util.Scanner;

/**
* One input object scanner
* File
* Collection Object ArrayList
* @author Li Zhangyong
*
*/
public class Add {
Private Scanner sc=new Scanner (system.in);
Private file File=new file (filepath.path_name);
Private arraylist<employ> EMS;


Public Add () {
if (file.exists ()) {
try {
ObjectInputStream ois=new ObjectInputStream (new FileInputStream (file));
try {
Ems= (arraylist<employ>) ois.readobject ();
Ois.close ();
} catch (ClassNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}

} catch (FileNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
} catch (IOException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}

}else{
Ems=new arraylist<employ> ();
}
if (ems!=null) {
Add ();
}else{
SYSTEM.OUT.PRINTLN ("System internal problem, unable to operate");
Return
}

}

public boolean checknum (String idstr) {
Detecting input formats
if (Idstr==null | | idstr.equals ("")) {
SYSTEM.OUT.PRINTLN ("Illegal input, repeat");
return false;
}
Char[] Cs=idstr.tochararray ();
for (int i=0;i<cs.length;i++) {
if (cs[i]< ' 0 ' | | cs[i]> ' 9 ') {
SYSTEM.OUT.PRINTLN ("Input illegal, repeat");
return false;
}
}
return true;
}
Private String idstr;
public int Getrightnum () {
Idstr=sc.nextline ();
if (!checknum (IDSTR)) {
Getrightnum ();
}
int Id=integer.parseint (IDSTR);
return ID;
}

public void Askgoon () {
System.out.println ("Would you like to continue typing?") y/n ");
String Choice=sc.nextline ();

if ("Y". Equalsignorecase (choice)) {
Add ();
}else if ("N". Equalsignorecase (choice)) {
Save to File
SaveToFile ();
Return
}else{
System.out.println ("No this command, please re-select!") ");
Askgoon ();
}
}

public void SaveToFile () {
try {
ObjectOutputStream oos=new ObjectOutputStream (new FileOutputStream (file));
Oos.writeobject (EMS);
Oos.close ();
Test Print View
System.out.println ("add success");
SYSTEM.OUT.PRINTLN (EMS);
Return
} catch (FileNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
} catch (IOException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}
}


public void Add () {
System.out.println ("Please enter User id:");
Returns an integer
int Id=getrightnum ();

for (int i=0;i<ems.size (); i++) {
if (Id==ems.get (i). GetId ()) {
SYSTEM.OUT.PRINTLN ("ID already exists, please re-enter");
Add ();
}
}
System.out.println ("Please enter employee Name:");
String Name=sc.nextline ();
Employ em=new employ (id,name);
Ems.add (EM);

Ask if you want to continue typing
Askgoon ();

}
}

(2)

Package Empsystem;

Import Java.io.File;
Import Java.io.FileInputStream;
Import java.io.FileNotFoundException;
Import java.io.IOException;
Import Java.io.ObjectInputStream;
Import java.util.ArrayList;
Import Java.util.Scanner;

/**
* One input object scanner
* File
* Collection Object ArrayList
* @author Li Zhangyong
*
*/
public class Showemp {
Private Scanner sc=new Scanner (system.in);
Private file File=new file (filepath.path_name);
Private arraylist<employ> EMS;

Public Showemp () {
if (file.exists ()) {
try {
ObjectInputStream ois=new ObjectInputStream (new FileInputStream (file));
try {
Ems= (arraylist<employ>) ois.readobject ();
Ois.close ();
if (ems!=null) {
Show ();
}else{
SYSTEM.OUT.PRINTLN ("System internal problem, unable to operate");
Return
}

} catch (ClassNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}

} catch (FileNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
} catch (IOException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}

}else{
SYSTEM.OUT.PRINTLN ("Data file does not exist, cannot be viewed");
Return
}
}

public boolean checknum (String idstr) {
Detecting input formats
if (Idstr==null | | idstr.equals ("")) {
SYSTEM.OUT.PRINTLN ("Illegal input, repeat");
return false;
}
Char[] Cs=idstr.tochararray ();
for (int i=0;i<cs.length;i++) {
if (cs[i]< ' 0 ' | | cs[i]> ' 9 ') {
SYSTEM.OUT.PRINTLN ("Input illegal, repeat");
return false;
}
}
return true;
}
Private String idstr;
public int Getrightnum () {
Idstr=sc.nextline ();
if (!checknum (IDSTR)) {
Getrightnum ();
}
int Id=integer.parseint (IDSTR);
return ID;
}

public void Show () {
System.out.println ("View all employee input Y, view individual employee input n");
String Choice=sc.nextline ();
if ("Y". Equalsignorecase (choice)) {
SYSTEM.OUT.PRINTLN (EMS);
Return
}else if ("N". Equalsignorecase (choice)) {
System.out.println ("Please enter the ID of the member to be queried:");
int Id=getrightnum ();
if (Searchid.searchid (ID)!=null) {
SYSTEM.OUT.PRINTLN ("The employee information you are looking for is: \ n" +searchid.searchid (ID));
Return
}else{
System.out.println ("No such user");
Return
}
}else{
System.out.println ("No this command, please re-select!") ");
Show ();
}

}

}

(3)

Package Empsystem;

Import Java.io.File;
Import Java.io.FileInputStream;
Import java.io.FileNotFoundException;
Import Java.io.FileOutputStream;
Import java.io.IOException;
Import Java.io.ObjectInputStream;
Import Java.io.ObjectOutputStream;
Import java.util.ArrayList;
Import Java.util.Scanner;

/**
* One input object scanner
* File
* Collection Object ArrayList
* @author Li Zhangyong
*
*/
public class Modify {
Private Scanner sc=new Scanner (system.in);
Private file File=new file (filepath.path_name);
Private arraylist<employ> EMS;

Public Modify () {
if (file.exists ()) {
try {
ObjectInputStream ois=new ObjectInputStream (new FileInputStream (file));
try {
Ems= (arraylist<employ>) ois.readobject ();
Ois.close ();
if (ems!=null) {
Modify ();
}else{
SYSTEM.OUT.PRINTLN ("System internal problem, unable to operate");
Return
}

} catch (ClassNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}

} catch (FileNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
} catch (IOException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}

}else{
SYSTEM.OUT.PRINTLN ("Data file does not exist, cannot be viewed");
Return
}
}

public boolean checknum (String idstr) {
Detecting input formats
if (Idstr==null | | idstr.equals ("")) {
SYSTEM.OUT.PRINTLN ("Illegal input, repeat");
return false;
}
Char[] Cs=idstr.tochararray ();
for (int i=0;i<cs.length;i++) {
if (cs[i]< ' 0 ' | | cs[i]> ' 9 ') {
SYSTEM.OUT.PRINTLN ("Input illegal, repeat");
return false;
}
}
return true;
}
Private String idstr;
public int Getrightnum () {
Idstr=sc.nextline ();
if (!checknum (IDSTR)) {
Getrightnum ();
}
int Id=integer.parseint (IDSTR);
return ID;
}

public void SaveToFile () {
try {
ObjectOutputStream oos=new ObjectOutputStream (new FileOutputStream (file));
Oos.writeobject (EMS);
Oos.close ();
Test Print View
SYSTEM.OUT.PRINTLN ("modified successfully");
SYSTEM.OUT.PRINTLN (EMS);
Return

} catch (FileNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
} catch (IOException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}
}

public void Modify () {
System.out.println ("Please enter the user ID to be modified:");
int Id=getrightnum ();
if (Searchid.searchid (ID)!=null) {
System.out.println ("The name of the user before modification is:" +searchid.searchid (ID). GetName ());
System.out.println ("Please enter the modified name:");
String Name=sc.nextline ();
for (int i=0;i<ems.size (); i++) {
if (Id==ems.get (i). GetId ()) {
Ems.get (i). SetName (name);
SaveToFile ();
}
}
}else{
System.out.println ("No such user");
Return
}
}

}

(4)

Package Empsystem;

Import Java.io.File;
Import Java.io.FileInputStream;
Import java.io.FileNotFoundException;
Import Java.io.FileOutputStream;
Import java.io.IOException;
Import Java.io.ObjectInputStream;
Import Java.io.ObjectOutputStream;
Import java.util.ArrayList;
Import Java.util.Iterator;
Import Java.util.Scanner;

/**
* One input object scanner
* File
* Collection Object ArrayList
* @author Li Zhangyong
*
*/
public class Delete {
Private Scanner sc=new Scanner (system.in);
Private file File=new file (filepath.path_name);
Private arraylist<employ> EMS;

Public Delete () {
if (file.exists ()) {
try {
ObjectInputStream ois=new ObjectInputStream (new FileInputStream (file));
try {
Ems= (arraylist<employ>) ois.readobject ();
Ois.close ();
if (ems!=null) {
Delete ();
}else{
SYSTEM.OUT.PRINTLN ("System internal problem, unable to operate");
Return
}

} catch (ClassNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}

} catch (FileNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
} catch (IOException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}

}else{
SYSTEM.OUT.PRINTLN ("Data file does not exist, cannot be viewed");
Return
}
}

public boolean checknum (String idstr) {
Detecting input formats
if (Idstr==null | | idstr.equals ("")) {
SYSTEM.OUT.PRINTLN ("Illegal input, repeat");
return false;
}
Char[] Cs=idstr.tochararray ();
for (int i=0;i<cs.length;i++) {
if (cs[i]< ' 0 ' | | cs[i]> ' 9 ') {
SYSTEM.OUT.PRINTLN ("Input illegal, repeat");
return false;
}
}
return true;
}
Private String idstr;
public int Getrightnum () {
Idstr=sc.nextline ();
if (!checknum (IDSTR)) {
Getrightnum ();
}
int Id=integer.parseint (IDSTR);
return ID;
}

public void SaveToFile () {
try {
ObjectOutputStream oos=new ObjectOutputStream (new FileOutputStream (file));
Oos.writeobject (EMS);
Oos.close ();
System.out.println ("delete succeeded");
Test Print View
SYSTEM.OUT.PRINTLN (EMS);
Return

} catch (FileNotFoundException e) {
TODO auto-generated Catch block
E.printstacktrace ();
} catch (IOException e) {
TODO auto-generated Catch block
E.printstacktrace ();
}
}

public void Delete () {
System.out.println ("Please enter the employee ID to be deleted:");
int Id=getrightnum ();

if (Searchid.searchid (ID)!=null) {
System.out.println ("The name of the user before deletion is:" +searchid.searchid (ID). GetName ());
Iterator<employ> It=ems.iterator ();
while (It.hasnext ()) {
Employ Em=it.next ();
if (Id==em.getid ()) {
It.remove ();
SaveToFile ();
}
}
}else{
System.out.println ("No such user");
Return
}
}
}

The employee ingest system for Java projects