英文:
Why -from Java- JSON returns this error? Clearly is in the JSON deserialization, but I cannot find exactly where it occurs
问题
情况：
[![从 Postman，JSON 正确返回数据][1]][1]
[1]: https://i.stack.imgur.com/4Kk0J.png
服务器端：
允许读取所有位于 /api/articulos 下的请求体。
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(); // 始终返回一个文章
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("失败：" + 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; // 转换为千克
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)
.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("收到状态码为 " + response.statusCode());
System.out.println(response.bodyAsJsonArray());
} else {
System.out.println("发生错误：" + ar.cause().getMessage());
}
});
return itemsArticulo;
}
好的，这是代码。当扫描条形码时，我收到这个错误
0,750 | 0,750 | 20 | 021162
oct. 11, 2020 6:33:18 A. M. io.vertx.core.impl.ContextImpl
SEVERE: 未处理的异常
io.vertx.core.json.DecodeException: 解码失败：意外字符 ('<' (代码 60))：预期有效值 (JSON 字符串、数字、数组、对象或令牌 'null'、'true' 或 'false')
在 [源: (io.netty.buffer.ByteBufInputStream); 行: 1, 列: 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: 意外字符 ('<' (代码 60))：预期有效值 (JSON 字符串、数字、数组、对象或令牌 'null'、'true' 或 'false')
在 [源: (io.netty.buffer.ByteBufInputStream); 行: 1, 列: 2
<details>
<summary>英文:</summary>
**Situation:**
[![from Postman, JSON returns the data correctly][1]][1]
[1]: https://i.stack.imgur.com/4Kk0J.png
**Server side:**
Enables the reading of the request body for all routes under /api/articulos.
Router router = Router.router(vertx);
router.route("/api/articulos*").handler(BodyHandler.create());
router.get("/api/articulos/:cantcomp1/:cantcomp2/:tipoprod/:prodpadre").handler(bizArticulo::getOneReadingBarcode);
*Business*
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;
}
**Client-side**
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;
}
**Ok, that's the code. When scan the barcode I get this error**
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
Anyboy can help me?
TIA
Ernesto
</details>
# 答案1
**得分**: 1
你正在调用错误的端点（即 `/api/conceptos/` 而不是 `/api/articulos`）。
<br>
<br>
在帖子中提供的截图中，展示了一个正确的响应，显示了一个针对以下URL的响应：
192.168.0.15:8092/api/articulos/0.75/0.75/20/021162
但在你的代码中，却有如下部分：
client.get(PORT, HOST, "/api/conceptos/" + cantComp1 + "/" + cantComp2 + "/" + tipoProducto + "/" + productoPadre)
<details>
<summary>英文:</summary>
You are calling the wrong endpoint (i.e. `/api/conceptos/` instead of `/api/articulos`).
<br>
<br>
In the screenshot provided in the post, which illustrates a correct response, you are showing a response for url
192.168.0.15:8092/api/articulos/0.75/0.75/20/021162
but in the code you have
client.get(PORT, HOST, "/api/conceptos/" + cantComp1 + "/" + cantComp2 + "/" + tipoProducto + "/" + productoPadre)
</details>
# 答案2
**得分**: 0
根据我的经验，这个错误消息通常出现在你尝试将API响应反序列化为JSON时，但实际响应内容类似于：
```html
<html><body><h1>Resource not found</h1></body></html>
或者
<html><body><h1>Internal server error</h1></body></html>
并且在第一个字符<处解析失败。
对于你的情况，这可能发生在response.bodyAsJsonArray()处。
请为你调用的URL创建一个调试输出：
String url = "/api/conceptos/" + cantComp1 + "/" + cantComp2 + "/" + tipoProducto + "/" + productoPadre;
英文:
According to my experiences, this error message:
io.vertx.core.json.DecodeException: Failed to decode:Unexpected character ('<'
usualy happens when you try to deserialize an api response into a json, but indeed the response is something like:
<html><body><h1>Resource not found</h1></body></html>
or
<html><body><h1>Internal server error</h1></body></html>
and the parsing fails at the first char <
For your case, this happens at response.bodyAsJsonArray() probably.
please make a debug output for the url what you are calling:
String url = "/api/conceptos/" + cantComp1 + "/" + cantComp2 + "/" + tipoProducto + "/" + productoPadre;
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