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Implement hashCode method

suggest change

To implement the hashCode method of an object easily you could use the HashCodeBuilder class.

Selecting the fields: 

@Override
public int hashCode() {
    
    HashCodeBuilder builder = new HashCodeBuilder();
    builder.append(field1);
    builder.append(field2);
    builder.append(field3);
    
    return builder.hashCode();
}

Using reflection: 

@Override
public int hashCode() {
    return HashCodeBuilder.reflectionHashCode(this, false);
}

the boolean parameter indicates if it should use transient fields.

Using reflection avoiding some fields: 

@Override
public int hashCode() {
    return HashCodeBuilder.reflectionHashCode(this, "field1", "field2");
}
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Apache Commons Lang:
* Apache Commons Lang
* Implement equals method
* Implement hashCode method
* Implement toString method
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0 Inheritance
1 Getting started with Java
2 Streams
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84 The Classpath
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90 XML XPath Evaluation
91 Performance Tuning
92 Parallel programming with ForkJoin framework
93 Common Pitfalls
94 Non-Access Modifiers
95 Java Compiler
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97 Installing Java Standard Edition
98 Process
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100 Dates and Time using java.time
101 Fluent Interface
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103 Just in Time JIT compiler
104 FTP File Transfer Protocol
105 Java Native Access JNI
106 Modules
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117 Secure objects
118 Pitfalls - threads and concurrency
119 Splitting a string into fixed length parts
120 Pitfalls - nulls and NullPointerException
121 SecurityManager
122 JNDI
123 super keyword
124 java.util.Objects class
125 Java command: java and javaw
126 Atomic types
127 Floating Point Operations
128 Converting to and from strings
129 sun.misc.Unsafe
130 Java Memory Model
131 Java deployment
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133 Queues and deques
134 Runtime commands
135 NumberFormat
136 Security and Cryptograhy
137 Java Virtual Machine JVM
138 Unit Testing
139 JavaBean
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142 Java SE 8 Features
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144 Packages
145 Concurrency and Money
146 Concurrent Collections
147 Using ThreadPoolExecutor in multi-threaded applications
148 Java Editions, versions, releases and distributions
149 Dynamic method dispatch
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152 Generating Java Code
153 JShell
154 Benchmarks
155 Collection Factory Methods
156 Multi-release JAR files
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158 TreeMap and TreeSet
159 Sockets
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161 Using other scripting languages in Java
162 Functional interfaces
163 List vs. set
164 2D graphics
165 Reflection
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167 Enum Map
168 EnumSet class
169 Local Inner class
170 Java Print Service
171 Immutable class
172 String Tokenizer
173 File upload to S3 / AWS
174 Readers and writers
175 Hashtable
176 Enum starting with a number
177 SortedMap
178 WeakHashMap
179 LinkedHashMap
180 StringBuffer
181 Choosing Collections
182 C++ Comparison
183 CompletableFuture
184 Contributors