1　introduction 　1 2　creating and destroying objects　5 item 1: consider static factory methods instead of constructors　5 item 2: consider a builder when faced with many constructor parameters　11 item 3: enforce the singleton property with a private constructor or an enum type　17 item 4: enforce noninstantiability with a private constructor　19 item 5: avoid creating unnecessary objects　20 item 6: eliminate obsolete object references　24 item 7: avoid finalizers　27 3　methods common to all objects　33 item 8: obey the general contract when overriding equals　33 item 9: always override hashcode when you overrideequals　45 item 10: always override tostring　51 item 11: override clone judiciously　54 item 12: consider implementing comparable　62 4　classes and interfaces　67 item 13: minimize the accessibility of classes and members 67 item 14: in public classes, use accessor methods, not public fields　71 item 15: minimize mutability　73 item 16: favor composition over inheritance　81 item 17: design and document for inheritance or else prohibit it　87 item 18: prefer interfaces to abstract classes　93 item 19: use interfaces only to define types　98 item 20: prefer class hierarchies to tagged classes　100 item 21: use function objects to represent strategies　103 item 22: favor static member classes over nonstatic　106 5　generics　109 item 23: don't use raw types in new code　109 item 24: eliminate unchecked warnings　116 item 25: prefer lists to arrays　119 item 26: favor generic types　124 item 27: favor generic methods　129 item 28: use bounded wildcards to increase api flexibility　134 item 29: consider typesafe heterogeneous containers　142 6　enums and annotations　147 item 30: use enums instead of int constants　147 item 31: use instance fields instead of ordinals　158 item 32: use enumset instead of bit fields　159 item 33: use enummap instead of ordinal indexing　161 item 34: emulate extensible enums with interfaces　165 item 35: prefer annotations to naming patterns　169 item 36: consistently use the override annotation　176 item 37: use marker interfaces to define types　179 7　methods　181 item 38: check parameters for validity ..　181 item 39: make defensive copies when needed　184 item 40: design method signatures carefully　189 item 41: use overloading judiciously　191 item 42: use varargs judiciously　197 item 43: return empty arrays or collections, not nulls　201 item 44: write doc comments for all exposed api elements　203 8　general programming　209 item 45: minimize the scope of local variables　209 item 46: prefer for-each loops to traditional for loops　212 item 47: know and use the libraries　215 item 48: avoid float and double if exact answers are required　218 item 49: prefer primitive types to boxed primitives　221 item 50: avoid strings where other types are more appropriate　224 item 51: beware the performance of string concatenation　227 item 52: refer to objects by their interfaces　228 item 53: prefer interfaces to reflection　230 item 54: use native methods judiciously　233 item 55: optimize judiciously　234 item 56: adhere to generally accepted naming conventions　237 9　exceptions　241 item 57: use exceptions only for exceptional conditions　241 item 58: use checked exceptions for recoverable conditions and runtime exceptions for programming errors　244 item 59: avoid unnecessary use of checked exceptions　246 item 60: favor the use of standard exceptions　248 item 61: throw exceptions appropriate to the abstraction　250 item 62: document all exceptions thrown by each method　252 item 63: include failure-capture information in detail messages　254 item 64: strive for failure atomicity　256 item 65: don't ignore exceptions　258 10　concurrency　259 item 66: synchronize access to shared mutable data　259 item 67: avoid excessive synchronization　265 item 68: prefer executors and tasks to threads　271 item 69: prefer concurrency utilities to wait and notify　273 item 70: document thread safety　278 item 71: use lazy initialization judiciously　282 item 72: don't depend on the thread scheduler　286 item 73: avoid thread groups　288 11　serialization　289 item 74: implement serializable judiciously　289 item 75: consider using a custom serialized form　295 item 76: write readobject methods defensively　302 item 77: for instance control, prefer enum types toreadresolve　308 item 78: consider serialization proxies instead of serialized instances　312 appendix: items corresponding to first edition　317 references　321 index 　327