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<a class="article-series-header" href="javascript:void(0);">這篇文檔是系列文章的一部分</a>
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• 使用 Spring 和 JPA Criteria 構建 REST 查詢語言
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• 使用 Spring Data JPA Specifications 構建 REST 查詢語言
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• 使用 Spring Data JPA 和 Querydsl 構建 REST 查詢語言
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• 高級搜索操作 – REST 查詢語言 (當前文章)
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• REST 查詢語言 – 實現 OR 運算
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• REST 查詢語言與 RSQL 的結合
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• REST 查詢語言與 Querydsl Web 支持
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1. 概述
在本文中,我們將擴展我們在上一系列文章中開發的 REST 查詢語言,以包含更多搜索操作。
我們現在支持以下操作:相等、否定、大於、小於、以...開頭、以...結尾、包含和 LIKE。
請注意,我們探索了三種實現方案——JPA Criteria、Spring Data JPA Specifications 和 Query DSL;在本文中,我們將繼續使用 Specifications,因為它是一種清晰且靈活的方式來表示我們的操作。
2. SearchOperation 枚舉
首先,讓我們通過枚舉來定義對我們支持的各種搜索操作的更好表示:
public enum SearchOperation {
EQUALITY, NEGATION, GREATER_THAN, LESS_THAN, LIKE, STARTS_WITH, ENDS_WITH, CONTAINS;
public static final String[] SIMPLE_OPERATION_SET = { ":", "!", ">", "<", "~" };
public static SearchOperation getSimpleOperation(char input) {
switch (input) {
case ':':
return EQUALITY;
case '!':
return NEGATION;
case '>':
return GREATER_THAN;
case '<':
return LESS_THAN;
case '~':
return LIKE;
default:
return null;
}
}
}我們有兩組操作:
1. 簡單 – 可以用一個字符表示:
- 相等:用冒號 (:) 表示
- 否定:用感嘆號 (!) 表示
- 大於:用大於號 (>) 表示
- 小於:用小於號 (<) 表示
- 相似:用波浪線 (~) 表示
2. 複雜 – 需要使用多個字符來表示:
- 以...開始:用 (=prefix*) 表示
- 以...結束:用 (=*suffix) 表示
- 包含...:用 (=*substring*) 表示
我們還需要修改我們的 SearchCriteria 類,以使用新的 SearchOperation。
public class SearchCriteria {
private String key;
private SearchOperation operation;
private Object value;
}3. 修改 UserSpecification
現在,讓我們將新支持的操作包含到我們的 UserSpecification 實現中:
public class UserSpecification implements Specification<User> {
private SearchCriteria criteria;
@Override
public Predicate toPredicate(
Root<User> root, CriteriaQuery<?> query, CriteriaBuilder builder) {
switch (criteria.getOperation()) {
case EQUALITY:
return builder.equal(root.get(criteria.getKey()), criteria.getValue());
case NEGATION:
return builder.notEqual(root.get(criteria.getKey()), criteria.getValue());
case GREATER_THAN:
return builder.greaterThan(root.<String> get(
criteria.getKey()), criteria.getValue().toString());
case LESS_THAN:
return builder.lessThan(root.<String> get(
criteria.getKey()), criteria.getValue().toString());
case LIKE:
return builder.like(root.<String> get(
criteria.getKey()), criteria.getValue().toString());
case STARTS_WITH:
return builder.like(root.<String> get(criteria.getKey()), criteria.getValue() + "%");
case ENDS_WITH:
return builder.like(root.<String> get(criteria.getKey()), "%" + criteria.getValue());
case CONTAINS:
return builder.like(root.<String> get(
criteria.getKey()), "%" + criteria.getValue() + "%");
default:
return null;
}
}
}4. 存儲持久性測試
接下來,我們測試新的搜索操作 – 在存儲持久性級別上:
4.1. 比較相等性
在下面的示例中,我們將通過 用户名及其姓和名 來搜索用户:
@Test
public void givenFirstAndLastName_whenGettingListOfUsers_thenCorrect() {
UserSpecification spec = new UserSpecification(
new SearchCriteria("firstName", SearchOperation.EQUALITY, "john"));
UserSpecification spec1 = new UserSpecification(
new SearchCriteria("lastName", SearchOperation.EQUALITY, "doe"));
List<User> results = repository.findAll(Specification.where(spec).and(spec1));
assertThat(userJohn, isIn(results));
assertThat(userTom, not(isIn(results)));
}4.2. 否定測試
接下來,我們搜索那些名字中 不包含“john” 的用户:
@Test
public void givenFirstNameInverse_whenGettingListOfUsers_thenCorrect() {
UserSpecification spec = new UserSpecification(
new SearchCriteria("firstName", SearchOperation.NEGATION, "john"));
List<User> results = repository.findAll(Specification.where(spec));
assertThat(userTom, isIn(results));
assertThat(userJohn, not(isIn(results)));
}4.3. 查找年齡大於“25”的用户
接下來,我們將搜索年齡大於“25”的用户:
@Test
public void givenMinAge_whenGettingListOfUsers_thenCorrect() {
UserSpecification spec = new UserSpecification(
new SearchCriteria("age", SearchOperation.GREATER_THAN, "25"));
List<User> results = repository.findAll(Specification.where(spec));
assertThat(userTom, isIn(results));
assertThat(userJohn, not(isIn(results)));
}4.4. 測試從…開始
用户,其名字首字母為“jo”:
@Test
public void givenFirstNamePrefix_whenGettingListOfUsers_thenCorrect() {
UserSpecification spec = new UserSpecification(
new SearchCriteria("firstName", SearchOperation.STARTS_WITH, "jo"));
List<User> results = repository.findAll(spec);
assertThat(userJohn, isIn(results));
assertThat(userTom, not(isIn(results)));
}4.5. 測試結束於
接下來,我們將搜索所有其姓名為以“n”結尾的用户:
@Test
public void givenFirstNameSuffix_whenGettingListOfUsers_thenCorrect() {
UserSpecification spec = new UserSpecification(
new SearchCriteria("firstName", SearchOperation.ENDS_WITH, "n"));
List<User> results = repository.findAll(spec);
assertThat(userJohn, isIn(results));
assertThat(userTom, not(isIn(results)));
}4.6. 搜索包含內容
現在,我們將搜索所有姓名為包含“oh”的用户:
@Test
public void givenFirstNameSubstring_whenGettingListOfUsers_thenCorrect() {
UserSpecification spec = new UserSpecification(
new SearchCriteria("firstName", SearchOperation.CONTAINS, "oh"));
List<User> results = repository.findAll(spec);
assertThat(userJohn, isIn(results));
assertThat(userTom, not(isIn(results)));
}4.7. 測試範圍
最後,我們將搜索年齡在“20”到“25”之間的用户:
@Test
public void givenAgeRange_whenGettingListOfUsers_thenCorrect() {
UserSpecification spec = new UserSpecification(
new SearchCriteria("age", SearchOperation.GREATER_THAN, "20"));
UserSpecification spec1 = new UserSpecification(
new SearchCriteria("age", SearchOperation.LESS_THAN, "25"));
List<User> results = repository.findAll(Specification.where(spec).and(spec1));
assertThat(userJohn, isIn(results));
assertThat(userTom, not(isIn(results)));
}5. The UserSpecificationBuilder
現在持久化已完成並經過測試,我們把注意力轉向 Web 層。
我們將在此基礎上,利用上一篇文章中 UserSpecificationBuilder 的實現,整合新的搜索操作:
public class UserSpecificationsBuilder {
private List<SearchCriteria> params;
public UserSpecificationsBuilder with(
String key, String operation, Object value, String prefix, String suffix) {
SearchOperation op = SearchOperation.getSimpleOperation(operation.charAt(0));
if (op != null) {
if (op == SearchOperation.EQUALITY) {
boolean startWithAsterisk = prefix.contains("*");
boolean endWithAsterisk = suffix.contains("*");
if (startWithAsterisk && endWithAsterisk) {
op = SearchOperation.CONTAINS;
} else if (startWithAsterisk) {
op = SearchOperation.ENDS_WITH;
} else if (endWithAsterisk) {
op = SearchOperation.STARTS_WITH;
}
}
params.add(new SearchCriteria(key, op, value));
}
return this;
}
public Specification<User> build() {
if (params.size() == 0) {
return null;
}
Specification result = new UserSpecification(params.get(0));
for (int i = 1; i < params.size(); i++) {
result = params.get(i).isOrPredicate()
? Specification.where(result).or(new UserSpecification(params.get(i)))
: Specification.where(result).and(new UserSpecification(params.get(i)));
}
return result;
}
}6. UserController
接下來,我們需要修改我們的 UserController 以正確地解析新的操作:
@RequestMapping(method = RequestMethod.GET, value = "/users")
@ResponseBody
public List<User> findAllBySpecification(@RequestParam(value = "search") String search) {
UserSpecificationsBuilder builder = new UserSpecificationsBuilder();
String operationSetExper = Joiner.on("|").join(SearchOperation.SIMPLE_OPERATION_SET);
Pattern pattern = Pattern.compile(
"(\\w+?)(" + operationSetExper + ")(\p{Punct}?)(\\w+?)(\p{Punct}?),");
Matcher matcher = pattern.matcher(search + ",");
while (matcher.find()) {
builder.with(
matcher.group(1),
matcher.group(2),
matcher.group(4),
matcher.group(3),
matcher.group(5));
}
Specification<User> spec = builder.build();
return dao.findAll(spec);
}我們現在可以調用API並獲得任何組合條件的正確結果。例如,以下是一個使用API和查詢語言構建的複雜操作的示例:
http://localhost:8082/spring-rest-query-language/auth/users?search=firstName:jo*,age<25以及響應:
[{
"id":1,
"firstName":"john",
"lastName":"doe",
"email":"[email protected]",
"age":24
}]7. 搜索API測試
讓我們通過編寫API測試套件來確保我們的API正常工作。
首先,我們將配置測試以及數據初始化:
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(
classes = { ConfigTest.class, PersistenceConfig.class },
loader = AnnotationConfigContextLoader.class)
@ActiveProfiles("test")
public class JPASpecificationLiveTest {
@Autowired
private UserRepository repository;
private User userJohn;
private User userTom;
private final String URL_PREFIX = "http://localhost:8082/spring-rest-query-language/auth/users?search=";
@Before
public void init() {
userJohn = new User();
userJohn.setFirstName("John");
userJohn.setLastName("Doe");
userJohn.setEmail("[email protected]");
userJohn.setAge(22);
repository.save(userJohn);
userTom = new User();
userTom.setFirstName("Tom");
userTom.setLastName("Doe");
userTom.setEmail("[email protected]");
userTom.setAge(26);
repository.save(userTom);
}
private RequestSpecification givenAuth() {
return RestAssured.given().auth()
.preemptive()
.basic("username", "password");
}
}7.1. 比較相等性
首先,讓我們搜索一個名字為 “john”且姓氏為“doe”的用户:
@Test
public void givenFirstAndLastName_whenGettingListOfUsers_thenCorrect() {
Response response = givenAuth().get(URL_PREFIX + "firstName:john,lastName:doe");
String result = response.body().asString();
assertTrue(result.contains(userJohn.getEmail()));
assertFalse(result.contains(userTom.getEmail()));
}7.2. 測試否定
現在,我們將搜索那些其名字不是“john”的用户:
@Test
public void givenFirstNameInverse_whenGettingListOfUsers_thenCorrect() {
Response response = givenAuth().get(URL_PREFIX + "firstName!john");
String result = response.body().asString();
assertTrue(result.contains(userTom.getEmail()));
assertFalse(result.contains(userJohn.getEmail()));
}7.3. 比較大於 </h3
接下來,我們將查找年齡大於“25”的用户:
@Test
public void givenMinAge_whenGettingListOfUsers_thenCorrect() {
Response response = givenAuth().get(URL_PREFIX + "age>25");
String result = response.body().asString();
assertTrue(result.contains(userTom.getEmail()));
assertFalse(result.contains(userJohn.getEmail()));
}7.4. 測試從…開始
用户,其名字首字母為“jo”:
@Test
public void givenFirstNamePrefix_whenGettingListOfUsers_thenCorrect() {
Response response = givenAuth().get(URL_PREFIX + "firstName:jo*");
String result = response.body().asString();
assertTrue(result.contains(userJohn.getEmail()));
assertFalse(result.contains(userTom.getEmail()));
}7.5. 測試結束時
現在 – 姓名以“n”結尾的用户:
@Test
public void givenFirstNameSuffix_whenGettingListOfUsers_thenCorrect() {
Response response = givenAuth().get(URL_PREFIX + "firstName:*n");
String result = response.body().asString();
assertTrue(result.contains(userJohn.getEmail()));
assertFalse(result.contains(userTom.getEmail()));
}7.6. 測試包含
接下來,我們將搜索所有名字包含“oh”的用户:
@Test
public void givenFirstNameSubstring_whenGettingListOfUsers_thenCorrect() {
Response response = givenAuth().get(URL_PREFIX + "firstName:*oh*");
String result = response.body().asString();
assertTrue(result.contains(userJohn.getEmail()));
assertFalse(result.contains(userTom.getEmail()));
}7.7. 測試範圍
最後,我們將搜索年齡在“20”到“25”之間的用户:
@Test
public void givenAgeRange_whenGettingListOfUsers_thenCorrect() {
Response response = givenAuth().get(URL_PREFIX + "age>20,age<25");
String result = response.body().asString();
assertTrue(result.contains(userJohn.getEmail()));
assertFalse(result.contains(userTom.getEmail()));
}8. 結論
在本文中,我們已將 REST Search API 的查詢語言向前推進到 成熟、經過測試的生產級實現。我們現在支持各種各樣的操作和約束,這應該使我們能夠優雅地跨越任何數據集,並獲取我們正在尋找的精確資源。