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formatting the source code

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This commit is contained in:
Liesheng Long 2019-05-23 20:09:03 -04:00
parent 2c9c96a811
commit a5a99c28b1
9 changed files with 173 additions and 175 deletions
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64
core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/HandleOptionalTypeExample.java
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@ -5,37 +5,37 @@ import java.util.Map;
import java.util.Optional; import java.util.Optional;
public class HandleOptionalTypeExample { public class HandleOptionalTypeExample {
static Map<String, User> usersByName = new HashMap(); static Map<String, User> usersByName = new HashMap();
static { static {
User user1 = new User(); User user1 = new User();
user1.setUserId(1l); user1.setUserId(1l);
user1.setFirstName("baeldung"); user1.setFirstName("baeldung");
usersByName.put("baeldung", user1); usersByName.put("baeldung", user1);
} }
public static void main(String[] args) {
changeUserName("baeldung", "baeldung-new");
changeUserName("user", "user-new");
}
public static void changeUserName(String oldFirstName, String newFirstName) {
Optional<User> userOpt = findUserByName(oldFirstName);
if(userOpt.isPresent()){
User user = userOpt.get();
user.setFirstName(newFirstName);
System.out.println("user with name "+oldFirstName+" is changed to "+ user.getFirstName());
} else {
//user is missing
System.out.println("user with name "+oldFirstName+" is not found.");
}
}
public static Optional<User> findUserByName(String name){
//look up the user in the database, the user object below could be null
User user=usersByName.get(name);
Optional<User> opt = Optional.ofNullable(user);
return opt; public static void main(String[] args) {
} changeUserName("baeldung", "baeldung-new");
changeUserName("user", "user-new");
}
public static void changeUserName(String oldFirstName, String newFirstName) {
Optional<User> userOpt = findUserByName(oldFirstName);
if (userOpt.isPresent()) {
User user = userOpt.get();
user.setFirstName(newFirstName);
System.out.println("user with name " + oldFirstName + " is changed to " + user.getFirstName());
} else {
// user is missing
System.out.println("user with name " + oldFirstName + " is not found.");
}
}
public static Optional<User> findUserByName(String name) {
// look up the user in the database, the user object below could be null
User user = usersByName.get(name);
Optional<User> opt = Optional.ofNullable(user);
return opt;
}
} }

25
core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/OptionalToJsonExample.java
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@ -4,17 +4,16 @@ import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.ObjectMapper;
public class OptionalToJsonExample { public class OptionalToJsonExample {
public static void main(String[] args) { public static void main(String[] args) {
UserOptional user = new UserOptional(); UserOptional user = new UserOptional();
user.setUserId(1l); user.setUserId(1l);
user.setFirstName("Bael Dung"); user.setFirstName("Bael Dung");
ObjectMapper om = new ObjectMapper(); ObjectMapper om = new ObjectMapper();
try { try {
System.out.print("user in json is:"+om.writeValueAsString(user)); System.out.print("user in json is:" + om.writeValueAsString(user));
} catch (JsonProcessingException e) { } catch (JsonProcessingException e) {
// TODO Auto-generated catch block e.printStackTrace();
e.printStackTrace(); }
} }
}
} }

32
core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java
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@ -7,20 +7,20 @@ import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence; import javax.persistence.Persistence;
public class PersistOptionalTypeExample { public class PersistOptionalTypeExample {
static String persistenceUnit = "com.baeldung.optionalReturnType"; static String persistenceUnit = "com.baeldung.optionalReturnType";
static EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnit); static EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnit);
static EntityManager entityManager = emf.createEntityManager(); static EntityManager entityManager = emf.createEntityManager();
//to run this app, uncomment the follow line in META-INF/persistence.xml // to run this app, uncomment the follow line in META-INF/persistence.xml
//<class>com.baeldung.optionalReturnType.UserOptionalField</class> // <class>com.baeldung.optionalReturnType.UserOptionalField</class>
public static void main(String[] args) { public static void main(String[] args) {
UserOptionalField user1 = new UserOptionalField(); UserOptionalField user1 = new UserOptionalField();
user1.setUserId(1l); user1.setUserId(1l);
user1.setFirstName(Optional.of("Bael Dung")); user1.setFirstName(Optional.of("Bael Dung"));
entityManager.persist(user1); entityManager.persist(user1);
UserOptional user2 = entityManager.find(UserOptional.class, 1l); UserOptional user2 = entityManager.find(UserOptional.class, 1l);
System.out.print("User2.firstName:"+user2.getFirstName()); System.out.print("User2.firstName:" + user2.getFirstName());
} }
} }

28
core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample2.java
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@ -5,18 +5,18 @@ import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence; import javax.persistence.Persistence;
public class PersistOptionalTypeExample2 { public class PersistOptionalTypeExample2 {
static String persistenceUnit = "com.baeldung.optionalReturnType"; static String persistenceUnit = "com.baeldung.optionalReturnType";
static EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnit); static EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnit);
static EntityManager em = emf.createEntityManager(); static EntityManager em = emf.createEntityManager();
public static void main(String[] args) { public static void main(String[] args) {
UserOptional user1 = new UserOptional(); UserOptional user1 = new UserOptional();
user1.setUserId(1l); user1.setUserId(1l);
user1.setFirstName("Bael Dung"); user1.setFirstName("Bael Dung");
em.persist(user1); em.persist(user1);
UserOptional user2 = em.find(UserOptional.class, 1l); UserOptional user2 = em.find(UserOptional.class, 1l);
System.out.print("User2.firstName:"+user2.getFirstName()); System.out.print("User2.firstName:" + user2.getFirstName());
} }
} }

28
core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserExample.java
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@ -5,18 +5,18 @@ import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence; import javax.persistence.Persistence;
public class PersistUserExample { public class PersistUserExample {
static String persistenceUnit = "com.baeldung.optionalReturnType"; static String persistenceUnit = "com.baeldung.optionalReturnType";
static EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnit); static EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnit);
static EntityManager em = emf.createEntityManager(); static EntityManager em = emf.createEntityManager();
public static void main(String[] args) { public static void main(String[] args) {
User user1 = new User(); User user1 = new User();
user1.setUserId(1l); user1.setUserId(1l);
user1.setFirstName("Bael Dung"); user1.setFirstName("Bael Dung");
em.persist(user1); em.persist(user1);
User user2 = em.find(User.class, 1l); User user2 = em.find(User.class, 1l);
System.out.print("User2.firstName:"+user2.getFirstName()); System.out.print("User2.firstName:" + user2.getFirstName());
} }
} }

61
core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/SerializeOptionalTypeExample.java
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@ -6,37 +6,36 @@ import java.io.ObjectOutputStream;
import java.util.Optional; import java.util.Optional;
public class SerializeOptionalTypeExample { public class SerializeOptionalTypeExample {
public static void main(String[] args) { public static void main(String[] args) {
User user1 = new User(); User user1 = new User();
user1.setUserId(1l); user1.setUserId(1l);
user1.setFirstName("baeldung"); user1.setFirstName("baeldung");
serializeObject(user1, "user1.ser");
UserOptionalField user2 = new UserOptionalField(); serializeObject(user1, "user1.ser");
user2.setUserId(1l);
user2.setFirstName(Optional.of("baeldung"));
serializeObject(user2, "user2.ser");
} UserOptionalField user2 = new UserOptionalField();
user2.setUserId(1l);
public static void serializeObject(Object object, String fileName) { user2.setFirstName(Optional.of("baeldung"));
// Serialization
try { serializeObject(user2, "user2.ser");
FileOutputStream file = new FileOutputStream(fileName);
ObjectOutputStream out = new ObjectOutputStream(file); }
out.writeObject(object); public static void serializeObject(Object object, String fileName) {
// Serialization
out.close(); try {
file.close(); FileOutputStream file = new FileOutputStream(fileName);
ObjectOutputStream out = new ObjectOutputStream(file);
System.out.println("Object "+object.toString()+ " has been serialized to file "+fileName);
out.writeObject(object);
} catch(IOException e) {
e.printStackTrace(); out.close();
} file.close();
}
System.out.println("Object " + object.toString() + " has been serialized to file " + fileName);
} catch (IOException e) {
e.printStackTrace();
}
}
} }

36
core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/User.java
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@ -7,25 +7,25 @@ import javax.persistence.Id;
@Entity @Entity
public class User implements Serializable { public class User implements Serializable {
@Id @Id
private long userId; private long userId;
private String firstName;
public long getUserId() {
return userId;
}
public void setUserId(long userId) { private String firstName;
this.userId = userId;
}
public String getFirstName() { public long getUserId() {
return firstName; return userId;
} }
public void setUserId(long userId) {
this.userId = userId;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
} }

40
core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptional.java
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@ -9,27 +9,27 @@ import javax.persistence.Id;
@Entity @Entity
public class UserOptional implements Serializable { public class UserOptional implements Serializable {
@Id @Id
private long userId; private long userId;
@Column(nullable = true)
private String firstName;
public long getUserId() {
return userId;
}
public void setUserId(long userId) { @Column(nullable = true)
this.userId = userId; private String firstName;
}
public Optional<String> getFirstName() { public long getUserId() {
return Optional.ofNullable(firstName); return userId;
} }
public void setUserId(long userId) {
this.userId = userId;
}
public Optional<String> getFirstName() {
return Optional.ofNullable(firstName);
}
public void setFirstName(String firstName) {
this.firstName = firstName;
Optional.ofNullable(firstName);
}
public void setFirstName(String firstName) {
this.firstName = firstName;
Optional.ofNullable(firstName);
}
} }

34
core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptionalField.java
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@ -8,24 +8,24 @@ import javax.persistence.Id;
@Entity @Entity
public class UserOptionalField implements Serializable { public class UserOptionalField implements Serializable {
@Id @Id
private long userId; private long userId;
private Optional<String> firstName;
public long getUserId() {
return userId;
}
public void setUserId(long userId) { private Optional<String> firstName;
this.userId = userId;
}
public Optional<String> getFirstName() { public long getUserId() {
return firstName; return userId;
} }
public void setFirstName(Optional<String> firstName) { public void setUserId(long userId) {
this.firstName = firstName; this.userId = userId;
} }
public Optional<String> getFirstName() {
return firstName;
}
public void setFirstName(Optional<String> firstName) {
this.firstName = firstName;
}
} }