社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 7624阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* 0o!Egq_  
**SiteFileFetch.java _nW#Cl~  
*/ E7Pz~6  
package NetFox; ]+78 "(  
import java.io.*; SQBe}FlktK  
import java.net.*; rcMSso2  
lGN{1djT  
&q[`lIV,L  
public class SiteFileFetch extends Thread { 2HREO@._)  
g"v-hTx  
z/S}z4o/  
SiteInfoBean siteInfoBean = null; //文件信息Bean U{.yX7  
long[] nStartPos; //开始位置 Z:%~Al:  
long[] nEndPos; //结束位置 /4 -6V d"8  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 sZPA(N?  
long nFileLength; //文件长度 [,ns/*f3R  
boolean bFirst = true; //是否第一次取文件 d#3E'8  
boolean bStop = false; //停止标志 Hk|wO:7Be  
File tmpFile; //文件下载的临时信息 5@@ilvwzz  
DataOutputStream output; //输出到文件的输出流 xrl!$xE GX  
O9[Dae{i  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) nx'D&, VX  
public SiteFileFetch(SiteInfoBean bean) throws IOException w+3-j  
{ z0-`D.D@\  
siteInfoBean = bean; ^NiS7)FX  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); b$1W>  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); .qk_m-o  
if(tmpFile.exists ()) A^"( VaK  
{ e47N9&4  
bFirst = false; 1$ C\ `  
read_nPos(); 2i_k$-  
} u IGeSd5B  
else Z |CL:)h  
{ #Rcb iV*M  
nStartPos = new long[bean.getNSplitter()]; |.Y}2>{  
nEndPos = new long[bean.getNSplitter()]; P+nd?:cz  
} aqzIMOAf  
RW04>oxVn  
8!(09gW'>  
g/6>>p`J  
} yd4\%%]  
m_g2Cep  
v46 5Z  
public void run() {:0TiOP5x  
{ ^9*kZV<K  
//获得文件长度 <*5 5d2  
//分割文件 TmIw?#q^  
//实例FileSplitterFetch ;X XB^,  
//启动FileSplitterFetch线程 Y<0R5rO  
//等待子线程返回 CDU$Gi  
try{ UiLiy?EJ  
if(bFirst) qz<>9n@o  
{ %RS8zN  
nFileLength = getFileSize(); w[X/|O  
if(nFileLength == -1) V*1hoC#  
{ . +  
System.err.println("File Length is not known!"); r0 fxEYze&  
} !m<v@SmL\  
else if(nFileLength == -2) 6_wj,7  
{ *kE<7  
System.err.println("File is not access!"); dF<GuS;l5  
} 3"HW{=  
else U+FI^Xrt#  
{ EAPjQA-B?  
for(int i=0;i<nStartPos.length;i++) + #V.6i  
{ 1 ms(03dp  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 1rLK1X  
} yrVk$k#6}  
for(int i=0;i<nEndPos.length-1;i++) (AI 4a+  
{ A5[iFT>  
nEndPos = nStartPos[i+1]; Z_.xglq{  
} V>Vu)7  
nEndPos[nEndPos.length-1] = nFileLength; 6( 0ME$  
} JULns#tx}  
} e"O c  
+l)[A{  
l1I\khS  
//启动子线程 UHT2a9rG  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [ qx[ 0  
for(int i=0;i<nStartPos.length;i++) 'YTSakNJ}  
{ x^]J^L45  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x@*!MC #  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x=%wP VJ  
nStartPos,nEndPos,i); D(&XmC[\Y  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >#Ue`)d`aY  
fileSplitterFetch.start(); f5o##ia7:  
} &6q67  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %-J} m  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &cHA xker  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .TpM3b#r  
nEndPos = " + nFileLength); fx3oA}  
// fileSplitterFetch[nPos.length-1].start(); >o,l/# z  
wMvAm%}+  
'}BYMEd/m%  
//等待子线程结束 }LTyXo  
//int count = 0; GMW,+  
//是否结束while循环 ;*[ oi  
boolean breakWhile = false; tx_h1[qi  
M>g%wg7Ah  
eB2a1<S&@  
while(!bStop) .6HHUy  
{ 8ZL9>"%l  
write_nPos(); -ztgirU  
Utility.sleep(500); gPqdl6#c  
breakWhile = true; E@[ZwTnJ  
NSkIzaNY  
%ki^XB86  
for(int i=0;i<nStartPos.length;i++) >&`;@ZOH  
{ Tx:S{n7&  
if(!fileSplitterFetch.bDownOver) 'Hv=\p4$1  
{ Z%$ tV3a?  
breakWhile = false; :[d *  
break; "rU 2g  
} 2`P=ekF]  
} !Y^3%B%  
if(breakWhile) `RHhc{  
break; Q|7l!YTzVu  
#fT<]j(  
Gc*p%2c  
//count++; :sA$LNj}  
//if(count>4) wrm ReT?  
// siteStop(); D/&nEMp6  
} G3${\'<  
05s{Z.aK  
&e)V!o@wJV  
System.err.println("文件下载结束!"); u{8:VX  
} [DD#YL\P  
catch(Exception e){e.printStackTrace ();} u#)ARCx,w  
} 5fY7[{ 2  
y134m  
OOZxs?pR  
//获得文件长度 ;i-<dAV8B  
public long getFileSize() 'bn$"A"{o  
{ 0HPqoen$  
int nFileLength = -1; *IQQsfL)  
try{ uy rS6e0  
URL url = new URL(siteInfoBean.getSSiteURL()); ?.Lq`~T`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p5`={'>-  
httpConnection.setRequestProperty("User-Agent","NetFox"); #u/5 nm  
LXS)(-&  
t7 +U!  
int responseCode=httpConnection.getResponseCode(); OJT%?P%@{  
if(responseCode>=400) Ef\&3TcQ  
{ ~%!"!Z4  
processErrorCode(responseCode); YckLz01jh  
return -2; //-2 represent access is error "'*Qq@!3?  
} xz3|m _)  
bx:j`5Uj`  
FO{?Z%& ;  
String sHeader; @&f~#Xe  
.f-s+J&ED  
|Ng}ZLBM  
for(int i=1;;i++) "5@\"L  
{ SQ-CdpT<  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e'T|5I0K  
//Utility.log(in.readLine()); 8;$zD]{D1  
sHeader=httpConnection.getHeaderFieldKey(i); d8J(~$tXQN  
if(sHeader!=null) SYA0Hiw7P  
{ !`0 El',gY  
if(sHeader.equals("Content-Length")) cCv@f ks  
{ tqXCj}mR  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1eOQ;#OV  
break; j2s{rQQ  
} ",pd 9  
} JYrOE "!h  
else +wGFJLHJ  
break; go?}M]c%7  
} Vc!'=&*  
} J[al4e^  
catch(IOException e){e.printStackTrace ();} _18Aek   
catch(Exception e){e.printStackTrace ();} @*=eqO  
AHet,N  
[ z,6K=  
Utility.log(nFileLength); h3j`X'  
<Y)Aez  
0?*":o30  
return nFileLength; ~(}n d  
} D-Q54"^3  
Zp+orc7  
9`cj9zz7  
//保存下载信息(文件指针位置) VJS1{n=;k  
private void write_nPos() ~\u~>mtchu  
{ / >O.U?  
try{ =8A L>:_  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,U.|+i{  
output.writeInt(nStartPos.length); / mwsF]Y  
for(int i=0;i<nStartPos.length;i++) ^%NjdZuDO  
{ jdd3[  
// output.writeLong(nPos); z-m:l;  
output.writeLong(fileSplitterFetch.nStartPos); 7ZFd;-  
output.writeLong(fileSplitterFetch.nEndPos); ne# %Gr  
} GpXU&A'r  
output.close(); zKFiCP K  
} TNlS2b1  
catch(IOException e){e.printStackTrace ();} &H/3@A3  
catch(Exception e){e.printStackTrace ();} @5{h+^  
} E&0]s  
Q&vU|y  
:oytJhxU  
//读取保存的下载信息(文件指针位置) &{S@v9~IT  
private void read_nPos() C,$7fW{?  
{ wLKC6@ W  
try{ <*z9:jz Q  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $.O(K4S  
int nCount = input.readInt(); * & : J  
nStartPos = new long[nCount]; s[%@3bY!7  
nEndPos = new long[nCount]; h%&2M58:  
for(int i=0;i<nStartPos.length;i++) m0]Lc{  
{ 8xx2+  
nStartPos = input.readLong(); $u, ~183  
nEndPos = input.readLong(); T1uOp5_]B  
} @gi / 1cq  
input.close(); 86 W.z6  
} JPq' C$  
catch(IOException e){e.printStackTrace ();} ,@aF#  
catch(Exception e){e.printStackTrace ();} ><{Lh@{  
} g3c,x kaO  
Bs\& '=l  
A[H"(E#k  
private void processErrorCode(int nErrorCode) D:XjJMW3r  
{ 2[1lwV  
System.err.println("Error Code : " + nErrorCode); R2y~+tko?  
} RC^k#+  
i*e'eZ;)  
\1oN't.  
//停止文件下载 "T.Qb/97@  
public void siteStop() CUx [LZR7m  
{ @|fT%Rwho<  
bStop = true; sK7b4gmK  
for(int i=0;i<nStartPos.length;i++) ):nC&M\W~  
fileSplitterFetch.splitterStop(); lz(}N7SLa  
^@;P-0Sy  
T_oL/x_;  
} ?:#$btmn?  
} K*N8Vpz(  
//负责部分文件的抓取 '19kP.  
**FileSplitterFetch.java oI x!?,1  
*/ Xd'B0kQaT  
package NetFox; 0(+dXzcwM  
~/;shs<9EM  
8xYeaK  
import java.io.*; }M &hcw<  
import java.net.*; 8 )= "Ee  
,ZvlK N  
9O-*iK  
public class FileSplitterFetch extends Thread { .>^U mM  
59k-,lyU,  
qwYq9A$+  
String sURL; //File URL gk4DoOj#P  
long nStartPos; //File Snippet Start Position PGA `R  
long nEndPos; //File Snippet End Position 43N=O FU  
int nThreadID; //Thread's ID I G B)  
boolean bDownOver = false; //Downing is over hc]5f3Z  
boolean bStop = false; //Stop identical  S=X_7V  
FileAccessI fileAccessI = null; //File Access interface A&:~dZ:%w  
VX e7b  
0yL%Pjn6  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7 '{wl,u  
{ 9Nu:{_YoP  
this.sURL = sURL; DpQ:U5j  
this.nStartPos = nStart; 1p(9hVA  
this.nEndPos = nEnd; X,`e1nsR  
nThreadID = id; _OJ19Ry  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1qhSN#s{_  
} TTz_w-68  
nh>lDfJV<  
$%"~.L4  
public void run() =5#sB*  
{ MzIn~[\  
while(nStartPos < nEndPos && !bStop) n4 J*04K  
{ 'Jl73#3  
90!67Ap`x  
E~1"Nh  
try{ .<.#g +  
URL url = new URL(sURL); Vn6]h|vm  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^qV6 khg  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^zR*s |1Q  
String sProperty = "bytes="+nStartPos+"-"; h2vD*W  
httpConnection.setRequestProperty("RANGE",sProperty); >\Ml \CyL  
Utility.log(sProperty); lM[FT=M  
M[?0 ^ FBx  
myDcr|j-a  
InputStream input = httpConnection.getInputStream(); ^(1S`z$  
//logResponseHead(httpConnection); io*iA<@Gx  
B S+=*3J  
n!%'%%o2v  
byte[] b = new byte[1024]; QP!0I01  
int nRead; $'Qv {  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "i; "  
{ ^MUvd  
nStartPos += fileAccessI.write(b,0,nRead); l6< bV#_qe  
//if(nThreadID == 1) }Bn`0;]  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d8M8O3  
} OLyl.#J  
zC_@wMWB  
VU \{<j{  
Utility.log("Thread " + nThreadID + " is over!"); JI|MR#_u  
bDownOver = true; sjwD x0(7=  
//nPos = fileAccessI.write (b,0,nRead); YY 8vhnw  
} $;B0x  
catch(Exception e){e.printStackTrace ();} f}VIkx]X"  
} .@3bz  
} ++Fk8R/$U[  
/@+[D{_Fw  
@;h$!w<  
//打印回应的头信息 YB"=eld  
public void logResponseHead(HttpURLConnection con) qp55U*  
{ c_FnJ_++f  
for(int i=1;;i++) ]?(_}""1  
{ [M&.'X  
String header=con.getHeaderFieldKey(i); 0i/!nke.  
if(header!=null) "i~~Q'=7  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i|QL6e*0  
Utility.log(header+" : "+con.getHeaderField(header)); >2dF^cDE-3  
else L<_zQ  
break; :x36Z4:  
} `E-cf7%  
} 's 'H&sa  
{}N=pL8MS  
i[m-&   
public void splitterStop() y~;w`5;|  
{ ::2(pgH  
bStop = true; SX@zDuM  
} @V qI+5TA  
@&GfCg5Cb  
.0iHI3i^  
} |ZJ<N\\h-  
%)!b254  
AIw<5lW  
/* qfsu# R  
**FileAccess.java ^ 9FRI9?  
*//文件访问(定位,写) fm&pxQjg  
package NetFox; H:_R[u4r  
import java.io.*; % n~ 'UA  
DE" Y(;S  
Jj,fdP#\  
public class FileAccessI implements Serializable{ j xTYW)E   
=w2_1F"  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QV9 z81[  
RandomAccessFile oSavedFile; ":V,&o9n  
long nPos; @szr '&\%A  
\cW9"e'  
52#Ac;Y  
public FileAccessI() throws IOException zt/N)5\V  
{ c@/K}  
this("",0); ?"L ^ 0%  
} 2^4OaHY88  
#D|n6[Y'.t  
6uKS!\EY|  
public FileAccessI(String sName,long nPos) throws IOException feG#*m2g  
{ =9L1Z \f  
oSavedFile = new RandomAccessFile(sName,"rw"); %)p?&_  
this.nPos = nPos; xDEjeM G  
oSavedFile.seek(nPos); EiCEB;*z|d  
} ^!sIEL  
bW^JR,  
gt)wk93d>  
public synchronized int write(byte[] b,int nStart,int nLen) ky=h7#wdv-  
{ !?5YXI,  
int n = -1; }B@44HdY  
try{ Am"e%|:  
oSavedFile.write(b,nStart,nLen); 2+cpNk$  
n = nLen; 'ocPG.PaU  
} B\Uocn  
catch(IOException e) Z,7VOf6g  
{ !8OgaMngzF  
e.printStackTrace (); hD9b2KZv  
} ciGJtD&P  
(0u(<qA\  
jj6yf.r6c  
return n; 7mtX/w9  
} RJOW#e :  
9A ?)n<3d  
:s>x~t8g#n  
} BV=~ !tsl  
y7| 3]>Z  
6os{q`/Q])  
/* cV:Ak~PKl  
**SiteInfoBean.java DIF-%X5  
*/ frT<9$QUL  
package NetFox; #eIFRNRb)  
~|( eh9  
OTzuOP 8  
public class SiteInfoBean { #*X\pjZ  
-{A*`.[v  
Fs&r ^ [/b  
private String sSiteURL; //Site's URL f"SK3hI$p  
private String sFilePath; //Saved File's Path CN:z *g  
private String sFileName; //Saved File's Name 3<HZ)w^B  
private int nSplitter; //Count of Splited Downloading File OJ r~iUr  
sW@_' Lw  
n&3}F?   
public SiteInfoBean() ZdgzPs"  
{//nSplitter的缺省值为5 tmi)LRF H  
//default value of nSplitter is 5 }CL7h;5N 3  
this("","","",5); ZlP+t>  
} 8kT`5`}lB  
7=gcdfW,;x  
!RSJb  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p0h E`!  
{ Lg{M<Q)4  
sSiteURL= sURL; -\n%K  
sFilePath = sPath; 5bBCI\&sam  
sFileName = sName; :l&Yq!5  
this.nSplitter = nSpiltter; f+1@mGt  
6ZfL-E{  
[0vqm:P  
} +QNsI2t;r  
8Qhj_  
.wB'"z8L  
public String getSSiteURL() 9{ #5~WP  
{ mM:%-I\$   
return sSiteURL; h"nhDART<  
} 3g3f87[  
AEkjyh\  
V-eRGSx  
public void setSSiteURL(String value) 5Dzf[V^]`  
{ voQJ!h1  
sSiteURL = value; No`*->R  
} mm;sf  
zK&1ti@wln  
v3]5`&3~  
public String getSFilePath() \&b 9  
{  TD%&9$F  
return sFilePath; )ZI#F]  
} bi^P k,'  
`][vaLd`Q  
u /]P  
public void setSFilePath(String value) %-a;HGbZn  
{ *V4%&&{  
sFilePath = value; @yo6w}3+-  
} ==Xy'n9'  
N`?|~g3  
U8J9 #+:  
public String getSFileName() (T%?@'\  
{ b $yIM  
return sFileName; b.v +5=)B  
} uVKe?~RC  
S~)`{ \  
<bb!BS&w  
public void setSFileName(String value) ?|98Y"w  
{ 3n)$\aBE  
sFileName = value; ,n[<[tkCR  
} 6<T:B[a-  
~M8|r!_  
Arm'0)B>  
public int getNSplitter() ;i\N!T{>  
{ oyr b.lu/  
return nSplitter; (xHu@l!]  
} ;mT}Q;F#  
^lt2,x   
Vjs'|%P7  
public void setNSplitter(int nCount) S3l^h4  
{ _cE_\Ay  
nSplitter = nCount; QS!Z*vG  
} jU~ x^Y  
} v/9DD%An  
?_d6 ;  
qB (Pqv  
/* a6j& po  
**Utility.java 3>^]r jFw  
*/ =Y81h-  
package NetFox; B}[f]8jrM  
HE-5e): k  
ZnRT$ l O  
public class Utility { '~Cn+xf4]  
cM3B5Lp  
M:GpyE%  
public Utility() !u@P\8M}  
{ NIVR;gm  
z?.9)T9_  
Vj9X6u}{  
} A5J41yH  
g i6s+2  
//线程睡眠 #Zw:&' QB  
public static void sleep(int nSecond) JJ7A` ;  
{ x<M::")5!V  
try{ ^;<d<V}*  
Thread.sleep(nSecond); bf0,3~G,P  
} D<d, 9S,)  
catch(Exception e) j :B/ FL  
{ &`@YdZtd"  
e.printStackTrace (); &TBFt;  
} Mq)]2>"v  
} 6"* <0  
Q;8z&4s@  
//日志 p$9Aadi]  
public static void log(String sMsg) k:Y\i]#yP  
{ lQ`=PFh  
System.err.println(sMsg); (&Rk#iU 2  
} (Fon!_$:  
M%`CzCL u  
mdEJ'];AH  
public static void log(int sMsg) 3?a`@C&x  
{ ?&#LmeZ}K  
System.err.println(sMsg); IZj`*M%3  
} ,{HQKHg  
} .)b<cH~%  
v,ZYh w  
&L$9Ii  
/* __'4Qt   
**TestMethod.java r[i^tIv6As  
*/ 7/IL" D  
package NetFox; (l^7EpNs  
&]o-ZZX  
]}! @'+=  
public class TestMethod { NplyvjQN;  
\L(cFjLIl  
!vAmjjB  
public TestMethod() e9{0hw7  
{ ///xx/weblogic60b2_win.exe E+O{^C=  
try{ ~dr,;NhOLJ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #j~FlY5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dYrgL3'  
SiteFileFetch fileFetch = new SiteFileFetch(bean); lf7bx}P*  
fileFetch.start(); bwXeEA@{  
} RH;ulAD6(~  
catch(Exception e){e.printStackTrace ();} 4n1g4c-   
CVa>5 vt  
ad: qOm  
} ~gd#cL%  
>NBc-DX^  
88osWo6rG  
public static void main(String[] args) -j3Lgm  
{ a ~v$ bNu  
new TestMethod(); PK2;Ywk`  
} =:s`C,l.4  
} {h+8^   
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
10+5=?,请输入中文答案:十五