差異處
這裏顯示兩個版本的差異處。
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java:jackson:annotation:jsonautodetect [2016/02/21 22:03] tony |
java:jackson:annotation:jsonautodetect [2023/06/25 09:48] |
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| - | {{tag>java jackson}} | ||
| - | ====== The visibility of the fields ====== | ||
| - | ===== Introduction ===== | ||
| - | 本篇文章在說明: | ||
| - | * 預設的輸出欄位顯示規則 | ||
| - | * 如何使用@JsonAutoDetect去改變欄位顯示規則 | ||
| - | ===== Default Visibility ===== | ||
| - | 在沒有特別設定的情況下，Jackson的Serializer是根據Get Method與Class的public data member決定欄位名稱。 | ||
| - | \\ | ||
| - | public data member: | ||
| - | <code java> | ||
| - | public String mName = "test"; | ||
| - | </code> | ||
| - | Output: | ||
| - | <code> | ||
| - | {"mName":"test"} | ||
| - | </code> | ||
| - | get method，boolean回傳值被稱為is-getter: | ||
| - | <code java> | ||
| - | public String getName(){ return "test"; } | ||
| - | public boolean isValid(){ return false; } | ||
| - | </code> | ||
| - | Output: | ||
| - | <code> | ||
| - | {"name":"test","valid":false} | ||
| - | </code> | ||
| - | ===== Use @JsonAutoDetect ===== | ||
| - | @JsonAutoDetect提供五種項目設定，其中creatorVisibility與setterVisibility的實際用途還不曉得，之後再研究: | ||
| - | * fieldVisibility: 針對data member。 | ||
| - | * getterVisibility: 針對getXXX()。 | ||
| - | * isGetterVisibility: 針對type為boolean的isXXX()。 | ||
| - | 預設情況下，成員變數必須宣告為public才會出現在結果。假如使用了fieldVisibility=Visibility.ANY，則會將private成員變數也輸出: | ||
| - | <code java> | ||
| - | @JsonAutoDetect(fieldVisibility=Visibility.ANY) | ||
| - | public static class AutoDetectObject { | ||
| - | private String mName ; | ||
| - | public AutoDetectObject(){ | ||
| - | |||
| - | } | ||
| - | private void setName(String aName){ | ||
| - | mName = aName; | ||
| - | } | ||
| - | |||
| - | public String getName(){ | ||
| - | return mName; | ||
| - | } | ||
| - | } | ||
| - | </code> | ||
| - | Output: | ||
| - | <code> | ||
| - | {"mName":"test","name":"test"} | ||
| - | </code> | ||
| - | 而getterVisibility與isGetterVisibility也類似，只是針對項目不同而已。 | ||
| - | ===== Reference ===== | ||
| - | * [[http://www.cowtowncoder.com/blog/archives/2011/02/entry_443.html|Filtering properties]] | ||
| - | * [[http://tutorials.jenkov.com/java-json/jackson-annotations.html|Jackson annotations]] | ||
| - | ===== ===== | ||
| - | ---- | ||
| - | \\ | ||
| - | ~~DISQUS~~ | ||
