BAEL-4499 - Synchronization bad practice and solution example

core-java-modules/core-java-concurrency-advanced-4/src/main/java/com/baeldung/synchronizationbadpractices/AnimalBadPractice.java

@@ -0,0 +1,35 @@
+package com.baeldung.synchronizationbadpractices;
+
+public class AnimalBadPractice {
+    
+    private String name;
+    private String owner;
+    
+    public String getName() {
+        return name;
+    }
+
+    public String getOwner() {
+        return owner;
+    }
+
+    public synchronized void setName(String name) {
+        this.name = name;
+    }
+    
+    public void setOwner(String owner) {
+        synchronized(this) {
+            this.owner = owner;
+        }
+    }
+    
+    public AnimalBadPractice() {
+        
+    }
+    
+    public AnimalBadPractice(String name, String owner) {
+        this.name = name;
+        this.owner = owner;
+    }
+    
+}

core-java-modules/core-java-concurrency-advanced-4/src/main/java/com/baeldung/synchronizationbadpractices/AnimalSolution.java

@@ -0,0 +1,42 @@
+package com.baeldung.synchronizationbadpractices;
+
+public class AnimalSolution { 
+    
+    private final Object objLock1 = new Object();
+    private final Object objLock2 = new Object();
+    
+    private String name;
+    private String owner;
+    
+    public String getName() {
+        return name;
+    }
+
+    public String getOwner() {
+        return owner;
+    }
+    
+    
+    public void setName(String name) {
+        synchronized(objLock1) {
+            this.name = name;
+        }
+    }
+     
+    public void setOwner(String owner) {
+        synchronized(objLock2) {
+            this.owner = owner;
+        }
+    }
+    
+    public AnimalSolution() {
+        
+    }
+    
+    public AnimalSolution(String name, String owner) {
+        this.name = name;
+        this.owner = owner;
+    }
+    
+
+}

core-java-modules/core-java-concurrency-advanced-4/src/main/java/com/baeldung/synchronizationbadpractices/SynchronizationBadPracticeExample.java

@@ -0,0 +1,51 @@
+package com.baeldung.synchronizationbadpractices;
+
+public class SynchronizationBadPracticeExample {
+
+    public void stringBadPractice1() { 
+        String stringLock = "LOCK_STRING"; 
+        synchronized (stringLock) { 
+            // ... 
+        }
+    }
+
+    private final String stringLock = "LOCK_STRING"; 
+    public void stringBadPractice2() { 
+        synchronized (stringLock) { 
+            // ... 
+        }
+    }
+
+    private final String internedStringLock = new String("LOCK_STRING").intern(); 
+    public void stringBadPractice3() { 
+        synchronized (internedStringLock) { 
+            // ... 
+        }
+    }
+
+    private final Boolean booleanLock = Boolean.FALSE; 
+    public void booleanBadPractice() { 
+        synchronized (booleanLock) { 
+            // ...
+        }
+    }
+
+    private int count = 0; 
+    private final Integer intLock = count; 
+    public void boxedPrimitiveBadPractice() { 
+        synchronized (intLock) { 
+            count++; 
+            // ...
+        }
+    }
+
+    public void classBadPractice() throws InterruptedException {
+        AnimalBadPractice animalObj = new AnimalBadPractice("Tommy", "John");
+        synchronized(animalObj) {
+            while (true) {
+                Thread.sleep(Integer.MAX_VALUE);
+            }
+        } 
+    }
+
+}

core-java-modules/core-java-concurrency-advanced-4/src/main/java/com/baeldung/synchronizationbadpractices/SynchronizationSolutionExample.java

@@ -0,0 +1,30 @@
+package com.baeldung.synchronizationbadpractices;
+
+public class SynchronizationSolutionExample {
+
+    private final String stringLock = new String("LOCK_STRING"); 
+    public void stringSolution() { 
+        synchronized (stringLock) { 
+            // ... 
+        }
+    }
+
+    private int count = 0;
+    private final Integer intLock = new Integer(count);
+    public void boxedPrimitiveSolution() {
+        synchronized(intLock) {
+            count++; 
+            // ... 
+        } 
+    }
+
+    private static int staticCount = 0;
+    private static final Object staticObjLock = new Object();
+    public void staticVariableSolution() {
+        synchronized(staticObjLock) {
+            staticCount++; 
+            // ... 
+        } 
+    }
+
+}