为什么JSON从Java返回这个错误?显然是在JSON反序列化中，但我找不到它发生的确切位置

Question

情况：[！[来自Postman，JSON正确返回数据][1]][1][1] ：https://i.stack.imgur.com/4Kk0J.png

服务器端：允许读取/api/ecleclos下所有路由的请求正文。

Router router = Router.router(vertx);
router.route("/api/articulos*").handler(BodyHandler.create());
router.get("/api/articulos/:cantcomp1/:cantcomp2/:tipoprod/:prodpadre").handler(bizArticulo::getOneReadingBarcode);

业务

private static final String SELECT_CBA = "select art.leyenda, $1 :: numeric as cantidad, uni.abreviatura, "
+ "round(((art.precio_costo * (art.utilidad_fraccionado/100)) + art.precio_costo) * ($2),2) as totpagar "
+ "FROM public.articulos art join public.unidades uni on uni.idunidad = art.idunidad "
+ "WHERE (substring(art.codigobarra,1,2) = ($3) and substring(art.codigobarra,3,6) = ($4))";

public void getOneReadingBarcode(RoutingContext routingContext) {
Double cantComprada1 = Double.parseDouble(routingContext.request().getParam("cantcomp1"));
Double cantComprada2 = Double.parseDouble(routingContext.request().getParam("cantcomp2"));
String tipoProducto = routingContext.request().getParam("tipoprod");
String productoPadre = routingContext.request().getParam("prodpadre");
HttpServerResponse response = routingContext.response();
pgClient
.preparedQuery(SELECT_CBA)
.execute(Tuple.of(cantComprada1, cantComprada2, tipoProducto, productoPadre), ar -> {
if (ar.succeeded()) {
RowSet<Row> rows = ar.result(); // return always ONE ARTICLE
List<Articulo> articulos = new ArrayList<>();
rows.forEach(row -> {
articulos.add(fromBarCode(row));
});
response.putHeader("content-type", "application/json; charset=utf-8")
.setStatusCode(200)
.end(Json.encodePrettily(articulos));
} else {
System.out.println("Failure: " + ar.cause().getMessage());
response.putHeader("content-type", "application/json; charset=utf-8")
.end(Json.encodePrettily(ar.cause().getMessage()));
}
});
}

private static Articulo fromBarCode(Row row) {
String leyenda = row.getString("leyenda");
BigDecimal cantComprada = row.getBigDecimal("cantidad");
String abreviatura = row.getString("abreviatura");
BigDecimal total_a_pagar = row.getBigDecimal("totpagar");
Articulo articulo = new Articulo();
articulo.setLeyenda(leyenda);
articulo.setCant_comprada(cantComprada);
articulo.setAbreviatura(abreviatura);
articulo.setTot_a_pagar(total_a_pagar);
return articulo;
}

客户端

private void validarArticulo() {
switch (txtCodigoBarra.getText().substring(0,2)) {
case "20":
Integer d = Integer.parseInt(txtCodigoBarra.getText().substring(8, 12));
Double decimal = d * 0.001; // convert to kilos
System.out.println(
String.format("%.3f", decimal) + " | " +
String.format("%.3f", decimal) + " | " +
txtCodigoBarra.getText().substring(0, 2)  + " | " +
txtCodigoBarra.getText().substring(2, 8)
);

PosAccess
.getCodigoBarra(
decimal,
decimal,
txtCodigoBarra.getText().substring(0, 2),
txtCodigoBarra.getText().substring(2, 8));
case "77":
}

public static ObservableList<Articulo> getCodigoBarra(Double cantComp1, Double cantComp2, String tipoProducto, String productoPadre) {
ObservableList<Articulo> itemsArticulo = FXCollections.observableArrayList();
WebClient client = WebClient.create(Vertx.vertx());
client
.get(PORT, HOST, "/api/conceptos/" + cantComp1 + "/" + cantComp2 + "/" + tipoProducto + "/" + productoPadre)
//      .get(PORT, HOST, "/api/conceptos/")
//      .setQueryParam("cantcomp1", cantComp1)
//      .addQueryParam("cantcomp2", cantComp2)
//      .addQueryParam("tipoproducto", tipoProducto)
//      .addQueryParam("productopadre", productoPadre)
.send(ar -> {
if (ar.succeeded()) {
HttpResponse<Buffer> response = ar.result();

response.bodyAsJsonArray().forEach(articulo -> {
JsonObject jo = (JsonObject) articulo;
itemsArticulo.add(new Articulo(jo.getString("leyenda"), jo.getDouble("cant_comprada"), jo.getString("abreviatura"), jo.getDouble("tot_a_pagar")));                  
});             

System.out.println("Received response with status code " + response.statusCode());
System.out.println(response.bodyAsJsonArray());
} else {
System.out.println("Something went wrong " + ar.cause().getMessage());
}
});
return itemsArticulo;
}

好的，这就是代码。扫描条形码时，我收到此错误

0,750 | 0,750 | 20 | 021162
oct. 11, 2020 6:33:18 A. M. io.vertx.core.impl.ContextImpl
SEVERE: Unhandled exception
io.vertx.core.json.DecodeException: Failed to decode:Unexpected character ('<' (code 60)): expected a valid value (JSON String, Number, Array, Object or token 'null', 'true' or 'false')
at [Source: (io.netty.buffer.ByteBufInputStream); line: 1, column: 2]
at io.vertx.core.json.jackson.JacksonCodec.fromParser(JacksonCodec.java:100)
at io.vertx.core.json.jackson.JacksonCodec.fromBuffer(JacksonCodec.java:67)
at io.vertx.ext.web.codec.impl.BodyCodecImpl.lambda$static$2(BodyCodecImpl.java:51)
at io.vertx.ext.web.client.impl.HttpResponseImpl.bodyAsJsonArray(HttpResponseImpl.java:116)
at consumer.PosAccess.lambda$0(PosAccess.java:45)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: com.fasterxml.jackson.core.JsonParseException: Unexpected character ('<' (code 60)): expected a valid value (JSON String, Number, Array, Object or token 'null', 'true' or 'false')
at [Source: (io.netty.buffer.ByteBufInputStream); line: 1, column: 2]
... 22 more

有男孩能帮我吗？TIA埃内斯托

Answer 1

您调用了错误的端点(即/api/conceptos/而不是/api/articulos(。

在帖子中提供的屏幕截图中，显示了正确的响应，您显示了url 的响应

192.168.0.15:8092/api/articulos/0.75/0.75/20/021162

但代码中有

client.get(PORT, HOST, "/api/conceptos/" + cantComp1 + "/" + cantComp2 + "/" + tipoProducto + "/" + productoPadre)

Answer 2

根据我的经验，此错误消息：

io.vertx.core.json.DecodeException: Failed to decode:Unexpected character ('<' 

通常，当您试图将api响应反序列化为json时，会发生这种情况，但实际上响应类似于：

<html><body><h1>Resource not found</h1></body></html>

或

<html><body><h1>Internal server error</h1></body></html>

并且在第一个字符<解析失败

对于您的情况，这种情况可能发生在response.bodyAsJsonArray()。

请为您正在调用的url做一个调试输出：

String url = "/api/conceptos/" + cantComp1 + "/" + cantComp2 + "/" + tipoProducto + "/" + productoPadre;