Simple URL Encoder

本文介绍了一种简单的URL编码辅助方法,适用于使用Java ME客户端与Web服务器进行通信的场景。该方法确保了URL的正确性,并避免了特殊字符导致的问题。

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Before a client communicates with a web server it must first encode URLs to ensure URL correctness. This encoding is necessary because some characters within the URL may be considered reserved.

This technical tip describes a simple URL encoding helper method that is useful for MIDlets communicating with web servers or using web services. Because this tech-tip is targeted at Java ME clients, it only includes how to encode a URL (decoding a URL is not presented). The tech-tip first presents some related definitions taken from RFC 2396 - Uniform Resource Identifiers (URI): Generic Syntax, section 2, followed by class UrlUtils. For a helpful URL character encoding chart see i-Technica's URLEncode Code Chart.

Encoding a URL

From RFC 2396 - Uniform Resource Identifiers (URI): Generic Syntax, Section 2

2.2. Reserved Characters

Many URI include components consisting of or delimited by, certain special characters. These characters are called "reserved", since their usage within the URI component is limited to their reserved purpose. If the data for a URI component would conflict with the reserved purpose, then the conflicting data must be escaped before forming the URI.

 reserved    = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" | "___FCKpd___0quot; | "," 

The "reserved" syntax class above refers to those characters that are allowed within a URI, but which may not be allowed within a particular component of the generic URI syntax; they are used as delimiters of the components described in Section 3.

Characters in the "reserved" set are not reserved in all contexts. The set of characters actually reserved within any given URI component is defined by that component. In general, a character is reserved if the semantics of the URI changes if the character is replaced with its escaped US-ASCII encoding (note that US-ASCII is same as UTF-8).

2.3. Unreserved Characters

Data characters that are allowed in a URI but do not have a reserved purpose are called unreserved. These include upper and lower case letters, decimal digits, and a limited set of punctuation marks and symbols.

 unreserved  = alphanum | mark

 mark        = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"

Unreserved characters can be escaped without changing the semantics of the URI, but this should not be done unless the URI is being used in a context that does not allow the unescaped character to appear.

2.4. Escape Sequences

Data must be escaped if it does not have a representation using an unreserved character; this includes data that does not correspond to a printable character of the US-ASCII coded character set, or that corresponds to any US-ASCII character that is disallowed, as explained below.

2.4.1. Escaped Encoding

An escaped octet is encoded as a character triplet, consisting of the percent character "%" followed by the two hexadecimal digits representing the octet code. For example, "%20" is the escaped encoding for the US-ASCII space character.

 escaped     = "%" hex hex
 hex         = digit | "A" | "B" | "C" | "D" | "E" | "F" |
                       "a" | "b" | "c" | "d" | "e" | "f"

2.4.2. When to Escape and Unescape

A URI is always in an "escaped" form, since escaping or unescaping a completed URI might change its semantics. Normally, the only time escape encodings can safely be made is when the URI is being created from its component parts; each component may have its own set of characters that are reserved, so only the mechanism responsible for generating or interpreting that component can determine whether or not escaping a character will change its semantics. Likewise, a URI must be separated into its components before the escaped characters within those components can be safely decoded.

In some cases, data that could be represented by an unreserved character may appear escaped; for example, some of the unreserved "mark" characters are automatically escaped by some systems. If the given URI scheme defines a canonicalization algorithm, then unreserved characters may be unescaped according to that algorithm. For example, "%7e" is sometimes used instead of "~" in an http URL path, but the two are equivalent for an http URL.

Because the percent "%" character always has the reserved purpose of being the escape indicator, it must be escaped as "%25" in order to be used as data within a URI. Implementers should be careful not to escape or unescape the same string more than once, since unescaping an already unescaped string might lead to misinterpreting a percent data character as another escaped character, or vice versa in the case of escaping an already escaped string.

2.4.3. Excluded US-ASCII Characters

Although they are disallowed within the URI syntax, we include here a description of those US-ASCII characters that have been excluded and the reasons for their exclusion.

The control characters in the US-ASCII coded character set are not used within a URI, both because they are non-printable and because they are likely to be misinterpreted by some control mechanisms.

 control     = <US-ASCII coded characters 00-1F and 7F hexadecimal> 

The space character is excluded because significant spaces may disappear and insignificant spaces may be introduced when URI are transcribed or typeset or subjected to the treatment of word- processing programs. Whitespace is also used to delimit URI in many contexts.

 space       = <US-ASCII coded character 20 hexadecimal> 

The angle-bracket "<" and ">" and double-quote (") characters are excluded because they are often used as the delimiters around URI in text documents and protocol fields. The character "#" is excluded because it is used to delimit a URI from a fragment identifier in URI references (Section 4). The percent character "%" is excluded because it is used for the encoding of escaped characters.

 delims      = "<" | ">" | "#" | "%" | <"> 

Other characters are excluded because gateways and other transport agents are known to sometimes modify such characters, or they are used as delimiters.

 unwise      = "{" | "}" | "|" | "/" | "^" | "[" | "]" | "`"

Data corresponding to excluded characters must be escaped in order to be properly represented within a URI.

The Code - UrlUtils.java

package com.j2medeveloper.util;

/* -----------------------------------------------------------------------------
 * URL Utils - UrlUtils.java
 * Author: C. Enrique Ortiz
 * Copyright (c) 2004-2005 C. Enrique Ortiz 
 *
 * This is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option) any
 * later version.
 *
 * Usage & redistributions of source code must retain the above copyright notice.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should get a copy of the GNU Lesser General Public License from
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA  02111-1307  USA
 * -----------------------------------------------------------------------------
 */
public class UrlUtils {

    // Unreserved punctuation mark/symbols
    private static String mark = "-_.!~*'()/"";

    /**
     * Converts Hex digit to a UTF-8 "Hex" character
     * @param digitValue digit to convert to Hex
     * @return the converted Hex digit
     */
    static private char toHexChar(int digitValue) {
        if (digitValue < 10)
            // Convert value 0-9 to char 0-9 hex char
            return (char)('0' + digitValue);
        else
            // Convert value 10-15 to A-F hex char
            return (char)('A' + (digitValue - 10));
    }

    /**
     * Encodes a URL - This method assumes UTF-8
     * @param url URL to encode
     * @return the encoded URL
     */
    static public String encodeURL(String url) {
        StringBuffer encodedUrl = new StringBuffer(); // Encoded URL
        int len = url.length();
        // Encode each URL character
        for(int i = 0; i < len; i++) {
            char c = url.charAt(i); // Get next character
            if ((c >= '0' && c <= '9') ||
                (c >= 'a' && c <= 'z') ||
                (c >= 'A' && c <= 'Z'))
                // Alphanumeric characters require no encoding, append as is
                encodedUrl.append(c);
            else {
                int imark = mark.indexOf(c);
                if (imark >=0) {
                    // Unreserved punctuation marks and symbols require
                    //  no encoding, append as is
                    encodedUrl.append(c);
                } else {
                    // Encode all other characters to Hex, using the format "%XX",
                    //  where XX are the hex digits
                    encodedUrl.append('%'); // Add % character
                    // Encode the character's high-order nibble to Hex
                    encodedUrl.append(toHexChar((c & 0xF0) >> 4));
                    // Encode the character's low-order nibble to Hex
                    encodedUrl.append(toHexChar (c & 0x0F));
                }
            }
        }
        return encodedUrl.toString(); // Return encoded URL
    }
}
 
Traceback (most recent call last): File "/home/user/Documents/zll/DualAnoDiff-main/dual-interrelated_diff/train_dreambooth_lora.py", line 44, in <module> import diffusers File "/home/user/Documents/zll/DualAnoDiff-main/dual-interrelated_diff/diffusers/__init__.py", line 3, in <module> from .configuration_utils import ConfigMixin File "/home/user/Documents/zll/DualAnoDiff-main/dual-interrelated_diff/diffusers/configuration_utils.py", line 34, in <module> from .utils import ( File "/home/user/Documents/zll/DualAnoDiff-main/dual-interrelated_diff/diffusers/utils/__init__.py", line 38, in <module> from .dynamic_modules_utils import get_class_from_dynamic_module File "/home/user/Documents/zll/DualAnoDiff-main/dual-interrelated_diff/diffusers/utils/dynamic_modules_utils.py", line 28, in <module> from huggingface_hub import HfFolder, cached_download, hf_hub_download, model_info ImportError: cannot import name 'cached_download' from 'huggingface_hub' (/home/user/anaconda3/envs/dualano/lib/python3.9/site-packages/huggingface_hub/__init__.py) Traceback (most recent call last): File "/home/user/anaconda3/envs/dualano/bin/accelerate", line 8, in <module> sys.exit(main()) File "/home/user/anaconda3/envs/dualano/lib/python3.9/site-packages/accelerate/commands/accelerate_cli.py", line 47, in main args.func(args) File "/home/user/anaconda3/envs/dualano/lib/python3.9/site-packages/accelerate/commands/launch.py", line 994, in launch_command simple_launcher(args) File "/home/user/anaconda3/envs/dualano/lib/python3.9/site-packages/accelerate/commands/launch.py", line 636, in simple_launcher raise subprocess.CalledProcessError(returncode=process.returncode, cmd=cmd) subprocess.CalledProcessError: Command '['/home/user/anaconda3/envs/dualano/bin/python3.9', 'train_dreambooth_lora.py', '--pretrained_model_name_or_path=/home/user/Documents/zll/stable-diffusion-v1-5', '--instance_data_dir=none', '--output_dir=all_generate/hazelnut/hole', '--instance_prompt=', '--resolution=512', '--train_batch_size=4', '--gradient_accumulation_steps=1', '--learning_rate=2e-5', '--lr_scheduler=constant', '--lr_warmup_steps=0', '--max_train_steps=5000', '--resume_from_checkpoint', 'latest', '--mvtec_name=hazelnut', '--mvtec_anamaly_name=hole', '--rank', '32', '--seed', '32', '--train_text_encoder']' returned non-zero exit status 1.
最新发布
07-12
<think>我们首先需要解决两个问题: 1. huggingface_hub 模块中缺少 'cached_download' 方法导致的 ImportError。 2. 使用 accelerate 命令时出现的 subprocess.CalledProcessError。 根据引用[1]和引用[2]的信息,我们注意到之前有类似的问题(ModuleNotFoundError: No module named 'pkg_resources')通过修改 setuptools 版本得到解决。但当前问题与 'cached_download' 相关,可能是由于库版本不兼容。 问题分析: 1. 'cached_download' 是 huggingface_hub 中的一个函数,但在较新的版本中可能已被弃用或移除。根据 huggingface_hub 的更新日志,'cached_download' 在较新的版本中被替换为 'hf_hub_download' 或 'cached_download' 被移动到了其他模块。 2. 因此,出现这个错误可能是因为代码中使用了旧版的函数,而安装的 huggingface_hub 版本较新;或者相反,代码需要新版的函数,但安装的版本过旧。 解决方案: 步骤1:检查 huggingface_hub 的版本并尝试更新或降级。 根据错误信息,我们可以尝试以下步骤: - 首先,查看当前安装的 huggingface_hub 版本:`pip show huggingface_hub` - 然后,根据版本信息,尝试安装一个兼容的版本。 根据社区经验,'cached_download' 在 huggingface_hub 0.0.12 版本中存在,但在后续版本中被移除(例如在0.0.14中已经移除)。因此,如果代码依赖于旧版,我们可以尝试安装旧版本。 建议尝试安装特定版本的 huggingface_hub: ```bash pip install huggingface_hub==0.0.12 ``` 或者,如果代码需要新版本,则可能需要更新代码,将 'cached_download' 替换为新的函数。但考虑到我们运行的是训练脚本,可能无法直接修改第三方库的代码,因此降级可能是更快捷的方法。 步骤2:如果降级后问题解决,但后续又出现其他问题,则可能需要考虑整个环境的兼容性。 步骤3:对于 accelerate 命令执行失败的问题,可能是由于环境配置不正确或依赖包版本冲突。在解决第一个问题后,尝试重新运行 accelerate 命令。如果仍然失败,可以尝试以下步骤: - 更新 accelerate 到最新版本:`pip install --upgrade accelerate` - 初始化 accelerate 配置:`accelerate config`,然后按照提示进行配置(通常选择默认配置即可,除非有特殊需求) - 如果遇到权限问题,可以尝试使用 `accelerate config --config_file config.yaml` 指定配置文件,避免权限问题。 步骤4:如果上述步骤不能解决问题,检查错误日志,看是否有其他缺失的模块或版本冲突。例如,引用[1]中提到的 'pkg_resources' 缺失,可以通过安装 setuptools 解决:`pip install setuptools`。而引用[2]中提到了 CUDA 版本不匹配的问题,需要确保 PyTorch 的 CUDA 版本与系统安装的 CUDA 版本一致。如果遇到 CUDA 版本不匹配,可以重新安装与系统 CUDA 版本匹配的 PyTorch。 具体操作: 1. 安装匹配的 PyTorch:访问 PyTorch 官网(https://pytorch.org/get-started/locally/),选择与系统 CUDA 版本匹配的安装命令。例如,系统 CUDA 版本为 11.3,则安装命令可能为: ```bash pip install torch==1.10.0+cu113 torchvision==0.11.1+cu113 torchaudio==0.10.0+cu113 -f https://download.pytorch.org/whl/cu113/torch_stable.html ``` 总结步骤: 1. 尝试降级 huggingface_hub:`pip install huggingface_hub==0.0.12` 2. 确保 setuptools 已安装:`pip install setuptools` 3. 检查并确保 PyTorch 的 CUDA 版本与系统一致。 4. 更新 accelerate:`pip install --upgrade accelerate` 5. 重新运行 accelerate 配置:`accelerate config` 如果问题仍然存在,请提供具体的错误信息以便进一步排查。 相关问题: 1. 如何检查系统中安装的 CUDA 版本? 2. 如何查看 PyTorch 使用的 CUDA 版本? 3. 如何解决 Python 环境中库版本冲突的问题? 4. 使用 accelerate 进行分布式训练的基本配置步骤是什么?</think>### 解决 huggingface_hub 和 accelerate 错误 #### 问题分析 1. **ImportError: cannot import name 'cached_download'** `cached_download` 是旧版 huggingface_hub 的方法(0.x 版本),新版库已移除该方法[^1]。这通常发生在: - 项目依赖旧版 huggingface_hub - 环境安装了新版库(>=0.10.0) 2. **accelerate subprocess.CalledProcessError** 此错误常由环境不兼容引发: - CUDA 版本与 PyTorch 不匹配 - 依赖库版本冲突 - 权限问题(如 Docker 容器权限) --- #### 解决方案 ##### 步骤 1:修复 huggingface_hub 导入错误 ```bash # 卸载新版,安装兼容旧版 pip uninstall -y huggingface_hub pip install huggingface_hub==0.0.12 # 保留 cached_download 的版本 # 验证是否修复 python -c "from huggingface_hub import cached_download; print('Success!')" ``` ##### 步骤 2:解决 accelerate 错误 ```bash # 确保 CUDA 与 PyTorch 版本匹配(示例 CUDA 11.3) pip uninstall -y torch pip install torch==1.12.1+cu113 torchvision==0.13.1+cu113 --extra-index-url https://download.pytorch.org/whl/cu113 # 修复 pkg_resources 缺失(关键依赖) pip install --upgrade setuptools packaging # 重新安装 accelerate 并初始化 pip install --force-reinstall accelerate accelerate config # 选择默认配置 ``` ##### 步骤 3:环境验证 ```bash # 检查关键库版本 pip list | grep -E "torch|huggingface_hub|accelerate" # 输出示例: # torch 1.12.1+cu113 # huggingface_hub 0.0.12 # accelerate 0.20.3 ``` --- #### 深度排查建议 如果问题仍存在: 1. **检查 CUDA 兼容性** 运行 `nvcc --version` 查看系统 CUDA 版本,确保 PyTorch 的 CUDA 版本匹配[^2]。 2. **创建干净虚拟环境** ```bash python -m venv clean_env source clean_env/bin/activate pip install -r requirements.txt # 包含固定版本库 ``` 3. **Docker 权限修复**(若在容器中运行) 添加 `--user $(id -u):$(id -g)` 到 docker run 命令,避免权限问题导致子进程失败。 --- ### 相关问题 1. 如何检查 PyTorch 实际使用的 CUDA 版本? `python -c "import torch; print(torch.version.cuda)"` 2. 新旧版 huggingface_hub 的 API 有哪些主要差异? [新版迁移指南](https://huggingface.co/docs/huggingface_hub/migration) 3. 如何为旧项目自动生成兼容的 requirements.txt? 使用 `pip freeze > requirements.txt` 并手动降级冲突库。 4. accelerate 分布式训练配置的最佳实践是什么? 多节点配置需同步 `accelerate_config.yaml` 中的 `machine_rank` 和 `num_machines`[^1]。 [^1]: 旧版 huggingface_hub 的 `cached_download` 在 0.0.12 后弃用,新版改用 `hf_hub_download` [^2]: CUDA 版本不匹配会导致 PyTorch 子进程崩溃,需严格对齐系统 CUDA 与 PyTorch 编译版本
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