How to Build Complex Search APIs with Bean Searcher in One Line of Code

Two Tables

Define a user table (id bigint, name varchar(45), age int, role_id int) and a role table (id int, name varchar(45)).

User Query Requirements

Filter by username with exact, full fuzzy, prefix, suffix matching and optional case‑insensitivity.

Filter by age with exact, greater‑than, less‑than, and range matching.

Filter by role ID (exact) and user ID (exact, same as age).

Select specific columns (e.g., id, name, role).

Support pagination, sorting by any field, and custom operators for each parameter.

Backend Interface Implementation

Using Bean Searcher the entire endpoint can be written in a single line of code, handling all the above requirements automatically.

Add Dependency

<code>&lt;dependency&gt;
    &lt;groupId&gt;com.ejlchina&lt;/groupId&gt;
    &lt;artifactId&gt;bean-searcher-boot-starter&lt;/artifactId&gt;
    &lt;version&gt;3.1.2&lt;/version&gt;
&lt;/dependency&gt;</code>

Entity Class

<code>@SearchBean(tables="user u, role r", joinCond="u.role_id = r.id", autoMapTo="u")
public class User {
    private Long id; // user ID
    private String name; // username
    private int age; // age
    private int roleId; // role ID
    @DbField("r.name")
    private String role; // role name
    // getters and setters ...
}</code>

Controller

<code>@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private MapSearcher mapSearcher;

    @GetMapping("/index")
    public SearchResult&lt;Map&lt;String, Object&gt;&gt; index(HttpServletRequest request) {
        // one line of code
        return mapSearcher.search(User.class, MapUtils.flat(request.getParameterMap()));
    }
}</code>

The

MapSearcher

interprets request parameters such as

name

,

name-op

,

age

,

age-op

,

size

,

page

,

sort

,

order

,

onlySelect

,

selectExclude

, etc., applying the appropriate operators (

eq

,

ne

,

gt

,

lt

,

ge

,

le

,

bt

,

mv

,

in

,

sw

,

ew

,

ey

,

ny

) and case‑insensitivity flags.

Examples:

GET /user/index – returns the first page with default size (15).

GET /user/index?size=10&page=2 – returns page 2 with 10 records per page.

GET /user/index?sort=ageℴ=desc – sorts results by age descending.

GET /user/index?onlySelect=id,name,role – returns only the specified columns.

GET /user/index?age=20&age-op=ge – filters users with age ≥ 20.

GET /user/index?name=Jack&name-op=sw&name-ic=true – case‑insensitive prefix match.

Bean Searcher also supports operator constraints (e.g., limiting a field to only

Equal

and

StartWith

), conditional exclusion of fields from WHERE clauses, and global parameter filters for custom preprocessing.