我有一个对象,它是“级别”对象的列表,我正在测试以两种方式使用 Spring Boot Rest Controller 传输它们:
对于 JSON,在 Rest Controller 中我使用类似的东西:
@RequestMapping(value = "/api/v1/layers/{layername}", method = RequestMethod.GET, produces = "application/json") public @ResponseBody List<Level> query(@PathVariable String layername, @RequestParam("northEastLat") Float northEastLat, @RequestParam("northEastLng") Float northEastLng, @RequestParam("northWestLat") Float northWestLat, @RequestParam("northWestLng") Float northWestLng, @RequestParam("southEastLat") Float southEastLat, @RequestParam("southEastLng") Float southEastLng, @RequestParam("southWestLat") Float southWestLat, @RequestParam("southWestLng") Float southWestLng ) { List<Level> poligons=levelService.obtainLevels(layername,southWestLng,southWestLat,northWestLng,northWestLat,northEastLng,northEastLat,southEastLng,southEastLat); int i=1; for (Level p : poligons) { System.out.println("poligon" + i++ + " is:" + p.toString()); } return poligons; }
对于 Protostuff Protobuf 格式,我使用如下内容:
@RequestMapping(value = "/api/v1/layers/{layername}", method = RequestMethod.GET,produces = "text/plain") public String query(@PathVariable String layername, @RequestParam("northEastLat") Float northEastLat, @RequestParam("northEastLng") Float northEastLng, @RequestParam("northWestLat") Float northWestLat, @RequestParam("northWestLng") Float northWestLng, @RequestParam("southEastLat") Float southEastLat, @RequestParam("southEastLng") Float southEastLng, @RequestParam("southWestLat") Float southWestLat, @RequestParam("southWestLng") Float southWestLng ) { List<Level> poligons=levelService.obtainLevels(layername,southWestLng,southWestLat,northWestLng,northWestLat,northEastLng,northEastLat,southEastLng,southEastLat); LevelList list = new LevelList(poligons); byte[] bytes; int i=1; for (Level p : poligons) { System.out.println("poligon" + i++ + " is:" + p.toString()); } Schema<LevelList> schema = RuntimeSchema.getSchema(LevelList.class); LinkedBuffer buffer = LinkedBuffer.allocate(); try { bytes = ProtostuffIOUtil.toByteArray(list, schema, buffer); } finally { buffer.clear(); } return new String(bytes); }
关卡对象格式为: [{"wkb_geometry":"{"类型":"多边形","坐标":[[[24.446822,45.34997],[24.706508,45.352485]]]}","id":199,"级别":"3 ","类型":空}
关卡对象是:
@Entity(name = "Level")
@Table(name="Level2G")
@SecondaryTables({
@SecondaryTable(name="Level3G"),
@SecondaryTable(name="Level4G")
})
public class Level implements Serializable {
private static final long serialVersionUID = 1L;
// @Column(name = "wkb_geometry",columnDefinition="Geometry")
//@Type(type = "org.hibernate.spatial.GeometryType")
@Column(name="wkb_geometry")
private /*Geometry */ String wkb_geometry;
@Id
@Column(name="id")
private Integer id;
@Column(name="level")
private String level;
@Transient
private String type;
public Level() {
}
public Level(String wkb_geometry, Integer id, String level) {
this.wkb_geometry = wkb_geometry;
this.id = id;
this.level = level;
this.type = "Feature";
}
public Level(String wkb_geometry, Integer id, String level, String type) {
this.wkb_geometry = wkb_geometry;
this.id = id;
this.level = level;
this.type = type;
}
public Object getWkb_geometry() {
return wkb_geometry;
}
public void setWkb_geometry(String wkb_geometry) {
this.wkb_geometry = wkb_geometry;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getLevel() {
return level;
}
public void setLevel(String level) {
this.level = level;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
@Override
public String toString() {
return "Level{" +
"wkb_geometry=" + wkb_geometry +
", id=" + id +
", level='" + level + '\'' +
", type='" + type + '\'' +
'}';
}
}
LevelList 对象只是 Level 对象的列表
问题是,与 JSON (3.7kb) 相比,Protostuff 获得了更大的有效负载 (26 kb)。为什么?
对于第二个选项,我也尝试设置“application/octet-stream”以直接返回字节,但结果仍然相同。我还比较了 JSON 和 protobuf 的速度;即使负载更大,protobuf 也具有更好的性能。知道为什么吗?
最佳答案
Protostuff 和 Protobuf 不是一回事。 Protostuff 是一个包装器库,可以使用许多不同的序列化格式。它还支持您似乎正在使用的运行时模式生成。该运行时模式需要随消息一起发送额外的元数据,以告诉接收者有关消息的模式。我猜您看到的大消息主要来自此运行时架构数据。
使用标准 Protobuf,模式不会随消息一起发送,因为假设发送者和接收者已经就编译到两个程序中的 .proto
文件提供的模式达成一致。如果您将 Protobuf 与标准 .proto
文件一起使用,您会发现它生成的消息比 JSON 小得多。
关于java - protobuf 负载比 JSON 大?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/38245281/