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
  • 11168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
/* c=gUY~Rl  
**SiteFileFetch.java Zl)|x%z  
*/ \?Z dUY  
package NetFox; JcP'+@X"  
import java.io.*; Jz6PqU|=  
import java.net.*; `}bUf epMJ  
?l/rg6mbI'  
x?kZD~|{)  
public class SiteFileFetch extends Thread { = N#WwNC  
WBGYk);  
!Zrvko  
SiteInfoBean siteInfoBean = null; //文件信息Bean &zR}jD>  
long[] nStartPos; //开始位置 VF-d^AGt  
long[] nEndPos; //结束位置 Am0$UeSZ  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 *=8)]_=f  
long nFileLength; //文件长度 _ :z~P<%s  
boolean bFirst = true; //是否第一次取文件 H_Yy.yi  
boolean bStop = false; //停止标志 :A$6Y*s\  
File tmpFile; //文件下载的临时信息 @P-7a`3*  
DataOutputStream output; //输出到文件的输出流 A28w/ =e7  
3O.-'U1K  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) khR3[ju{^  
public SiteFileFetch(SiteInfoBean bean) throws IOException I'gnw~  
{ MG6Tk(3S  
siteInfoBean = bean; \yqiv"'  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ;Cwn1N9S  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); gOkO8P6P8  
if(tmpFile.exists ()) WXM_H0K  
{ #df43_u  
bFirst = false; \=@}(<4  
read_nPos(); QqDF_  
} -H \nFJ6+  
else H`P )  
{ L81"W`?  
nStartPos = new long[bean.getNSplitter()]; (#:Si~3  
nEndPos = new long[bean.getNSplitter()];  LCG<  
} _YY)-H  
}LRAe3N%8  
I4*N  
^Iz.O  
} }X UHP%  
?:ZH%R_`a  
;(sb^O  
public void run() zb<+x(0y"  
{ [H& m@*UO  
//获得文件长度 ; ^$RG  
//分割文件 B}Qo8i7 z  
//实例FileSplitterFetch \8pbPo=x  
//启动FileSplitterFetch线程 g/E;OcFaO  
//等待子线程返回 >eXNw}_j  
try{ |LQmdgVr$  
if(bFirst) 9. R _=  
{ g (~&  
nFileLength = getFileSize(); M_e! s}F  
if(nFileLength == -1) ck}y-,>,[O  
{ b9U2afd  
System.err.println("File Length is not known!"); ql4T@r3l}3  
} c*h5lM'n6  
else if(nFileLength == -2) ,kP{3.#Q  
{ ^\!^#rO  
System.err.println("File is not access!"); RHxd6Gs"  
} 1~*_H_Q't  
else r}991O<  
{ sqy5rug  
for(int i=0;i<nStartPos.length;i++) RPrk]<<1  
{ 3lJK[V{'#'  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); aV ^2  
} 6QV/8IX  
for(int i=0;i<nEndPos.length-1;i++) O~D}&M@/R  
{ -&&mkK B!  
nEndPos = nStartPos[i+1]; !>+ 0/   
}  A=,m  
nEndPos[nEndPos.length-1] = nFileLength; lRrOoON  
} [:o#d`^  
} 0QPipuP  
e#AB0-f  
qj|GAGrQ2  
//启动子线程 q\~7z1   
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D Lu]d$G  
for(int i=0;i<nStartPos.length;i++) b"gYNGgX  
{ B!<I[fvK  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >8,BC  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <ZocMv9gM  
nStartPos,nEndPos,i); \C L`j  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h$k(|/+  
fileSplitterFetch.start(); T7,tJk,(  
} ^a(q7ZfY  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |9g*rO  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MDlC U  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >):b AfI  
nEndPos = " + nFileLength); R38 w!6{  
// fileSplitterFetch[nPos.length-1].start(); l})uYae/  
\!%3giD5!  
/eE P^)h  
//等待子线程结束 QCjmg5bf'7  
//int count = 0; CN >q`[!  
//是否结束while循环 %jkd}D  
boolean breakWhile = false; | zAey\  
cB<Zez  
gt ?&!S^  
while(!bStop) T.xW|Iwx  
{ CzK X}  
write_nPos(); rF5<x3  
Utility.sleep(500); UeVF@rw  
breakWhile = true; 6"wY;E  
0}ZuF.  
&K7g8x"x.  
for(int i=0;i<nStartPos.length;i++) g ` Wr3  
{ rg $71Ir  
if(!fileSplitterFetch.bDownOver) {c$W-t):U|  
{  $% jV%k  
breakWhile = false; M_PL{  
break; d BJM?/  
} b w cPY  
} /r)d4=1E  
if(breakWhile) 86I".R$d  
break; > 4^U=T#  
xv)7-jlx  
!is8`8F8  
//count++; ZpwB"%e$  
//if(count>4) G1D(-X4ALZ  
// siteStop(); Um|:AT}`^  
} s2tEyR+gW  
8g$ 8]'M^T  
V9MA)If>  
System.err.println("文件下载结束!"); <uAqb Wu  
} T"2ye9a  
catch(Exception e){e.printStackTrace ();} 'r-a:8:t^  
} kAAz|dhL-  
h\yYg'CC  
-j(/5.a  
//获得文件长度 aWit^dp  
public long getFileSize() h;B'#$_  
{ DZ EA*E>  
int nFileLength = -1; Sw0~6RZ  
try{  m.2  
URL url = new URL(siteInfoBean.getSSiteURL()); Y!SD^Ie7!  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Pukq{/27  
httpConnection.setRequestProperty("User-Agent","NetFox"); c,+oH<bZZs  
`T mIrc  
wp@c;gK7  
int responseCode=httpConnection.getResponseCode(); t!K|3>w  
if(responseCode>=400) tV<A u  
{ t!PFosFp  
processErrorCode(responseCode); 1e&`m~5K+  
return -2; //-2 represent access is error h[ t OY  
} 8`im4.~#%  
BtjsN22  
*:_.cbo  
String sHeader; ]-0 &[@I4@  
[H"Ods~_`  
79i>@u%  
for(int i=1;;i++) l5aQDkp}  
{ =7$YBCuF  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F[J;u/Z  
//Utility.log(in.readLine()); 7%o\O{,U  
sHeader=httpConnection.getHeaderFieldKey(i);  - @  
if(sHeader!=null) =EIsqk^*  
{ Hiw{1E:rW  
if(sHeader.equals("Content-Length")) OnD+/I  
{ ;ymUMQ%;/  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h'N,oDB)  
break; ]o_ Ps|  
} ]A_)&`"Cb  
} z`/v}'d[X  
else lfCoL@$6D  
break; ;KnnAZJ  
} <8H`y(S  
} [jafPi(#g  
catch(IOException e){e.printStackTrace ();} c|I{U[(U  
catch(Exception e){e.printStackTrace ();} xOS4J+'s@  
V+E2nJ  
ost~<4~  
Utility.log(nFileLength); |vGz 1jLV  
D F0~A  
2#sE\D  
return nFileLength; p[W8XX  
} or(Z-8a_  
Q~`]0R159e  
(}}BZ S&.  
//保存下载信息(文件指针位置) Ha;^U/0|  
private void write_nPos() 4$.4,4+  
{ 6W~F nJI  
try{ FzW(An&x2  
output = new DataOutputStream(new FileOutputStream(tmpFile)); aLP 2p]  
output.writeInt(nStartPos.length); ==c\* o  
for(int i=0;i<nStartPos.length;i++) l'$AmuGj  
{ ^gNAGQYA  
// output.writeLong(nPos); {y :/9  
output.writeLong(fileSplitterFetch.nStartPos); 7|H !(a'  
output.writeLong(fileSplitterFetch.nEndPos); 2&P'rmFm  
} fLPB *y6  
output.close(); 3:S Ex;d+  
} |3vQmd !2}  
catch(IOException e){e.printStackTrace ();} * \f(E#wa  
catch(Exception e){e.printStackTrace ();} ;@Ls "+g  
} .O~)zM x  
(3W<yAM+  
[ UQzCqV  
//读取保存的下载信息(文件指针位置) ?-*_v//g  
private void read_nPos() )=8X[<^i  
{ MTa.Ubs  
try{ _ 57m] ;&  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tz2`X V{  
int nCount = input.readInt(); ='YR;  
nStartPos = new long[nCount]; fNQ.FAK":  
nEndPos = new long[nCount]; fU$zG"a_  
for(int i=0;i<nStartPos.length;i++) xpUaFb  
{ HHT K{X+  
nStartPos = input.readLong(); rW!P~yk  
nEndPos = input.readLong(); \u:xDS(  
} L{osh0  
input.close(); :fo%)_Jc!  
} +xB !T1p D  
catch(IOException e){e.printStackTrace ();} R$NH [Tz  
catch(Exception e){e.printStackTrace ();} QIG MP=!j  
} z]~B@9l  
YpXUYNy  
(l9U7^S"{K  
private void processErrorCode(int nErrorCode) ]"aC wr  
{ L1M]ya!l  
System.err.println("Error Code : " + nErrorCode); OyFBM>6gh  
} ^- mz!{  
=|=9\3po  
X8F _Mb*  
//停止文件下载 8%2*RKj  
public void siteStop() /1t(e._  
{ v?5Xx{ym  
bStop = true; 0l{').!_  
for(int i=0;i<nStartPos.length;i++) 7w YSP&$  
fileSplitterFetch.splitterStop(); q4Qm: |-  
}hEBX:-  
Cd]d[{NJ;  
} j[9xF<I  
} IZniRd;  
//负责部分文件的抓取 %<:?{<~wH9  
**FileSplitterFetch.java [sbC6(z  
*/ :,6dW?mun6  
package NetFox; `dMl5b  
cKdy)T%;  
YtE V8w_$  
import java.io.*; M'Q{2%:>a  
import java.net.*; ?}lgwKBHl;  
@4_W}1W  
RCnN+b:c  
public class FileSplitterFetch extends Thread { ,RDxu7iT  
 E~jNUTq  
"\]kK @,  
String sURL; //File URL %TvunV7NQS  
long nStartPos; //File Snippet Start Position @D Qg1|m  
long nEndPos; //File Snippet End Position \snbU'lfP  
int nThreadID; //Thread's ID H>a3\M  
boolean bDownOver = false; //Downing is over VTy!<I  
boolean bStop = false; //Stop identical C KBLM2 D  
FileAccessI fileAccessI = null; //File Access interface pu,/GBG_  
rN8 ZQiJC  
'9]%#^[Q  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i8+kc_8#d  
{ u3w `(3{ <  
this.sURL = sURL; X Oc0j9Oa  
this.nStartPos = nStart; *!Vic#D%  
this.nEndPos = nEnd; A<QYW,:|  
nThreadID = id; )k- 7mwkZ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F;}?O==H;  
} `{<2{}2M  
C<eeAWP3v  
0 A/GWSmF  
public void run() O=G2bdY{,  
{ v5RS<?o  
while(nStartPos < nEndPos && !bStop) O"nY4  
{ Y:ZI9JK?  
WQ|d;[E  
3JWHyo  
try{ )j]S ;Mr  
URL url = new URL(sURL); 9v_gR52vh  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z#3wMK~  
httpConnection.setRequestProperty("User-Agent","NetFox"); TJ ;4QL  
String sProperty = "bytes="+nStartPos+"-"; w(<; $9  
httpConnection.setRequestProperty("RANGE",sProperty); VsNqYFHes&  
Utility.log(sProperty); #}^ZxEU  
T<mk98CdE  
K &Ht37T  
InputStream input = httpConnection.getInputStream(); 9L*gxI>  
//logResponseHead(httpConnection); &:nWZ!D  
mAX]m1s  
)U`H7\*)  
byte[] b = new byte[1024]; j}X4#{jgC  
int nRead; ^-f5;B`\i  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x\3tSP7Vp  
{ _Oh;._PS  
nStartPos += fileAccessI.write(b,0,nRead); _|g(BK2}  
//if(nThreadID == 1) Xa Yx avq  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H7H'0C  
} Gg{@]9  
p}}}~ lC/  
_+T;4U' p  
Utility.log("Thread " + nThreadID + " is over!"); *;1G+Q#  
bDownOver = true; #Jq@p_T"  
//nPos = fileAccessI.write (b,0,nRead); hUxpz:U*  
} cSnm\f  
catch(Exception e){e.printStackTrace ();} k9w<0h3  
} =uYSZR  
} 6jO*rseC  
iePpJ>(  
eWhv X9 <  
//打印回应的头信息 {Ejv8UdA9  
public void logResponseHead(HttpURLConnection con) Z8}Zhe.  
{ ACU0  
for(int i=1;;i++) P zzX Ds6  
{ e-]k{_wm  
String header=con.getHeaderFieldKey(i); (b GiBsb  
if(header!=null) |rq~.cA  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Sr,ZM1J  
Utility.log(header+" : "+con.getHeaderField(header)); M+ ^]j  
else pr>K#@^  
break; 6<(HT#=#  
} .[+8D=  
} mRW(]OFIai  
GLv}|>W  
tV[?WA[xt  
public void splitterStop() tkR^dC  
{ qF%wl  
bStop = true; &bRmr/D  
} ^8 AV#a  
'i%Azzv  
13}=;4O  
} W7O%.xP  
#:"\6s  
\I/l6H>o3  
/* XqyfeY5t  
**FileAccess.java _U.8\J2  
*//文件访问(定位,写) 23U9+  
package NetFox; &+J5GHt@  
import java.io.*; mucY+k1>g  
/:z}WAW  
0Dc$nL?TqX  
public class FileAccessI implements Serializable{ VS%8f.7ep  
l9qq;hhGP,  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 VrQw;-rQ  
RandomAccessFile oSavedFile; e1[kgp   
long nPos; lh(A=hn"n  
1&i!92:E  
''?.6r  
public FileAccessI() throws IOException nm*1JA.:  
{ OC 7:Dp4  
this("",0); }]=b%CPJh+  
} ZZ]/9oiF%  
zblh_6  
p!hewtb5  
public FileAccessI(String sName,long nPos) throws IOException -x:Wp*,  
{ r\'3q '7p  
oSavedFile = new RandomAccessFile(sName,"rw"); oT\B-lx  
this.nPos = nPos; u17Da9@;  
oSavedFile.seek(nPos); pZlBpGQf  
} zc*qmb  
( J\D"4q  
wrK$ZO]  
public synchronized int write(byte[] b,int nStart,int nLen) [<1i[\^  
{ dK|MQ <  
int n = -1; r1}7Q7-z  
try{ Hu1w/PLq  
oSavedFile.write(b,nStart,nLen); /n@_Ihx  
n = nLen; rYJt;/RtR}  
} Z !wDh_  
catch(IOException e) H+zQz8zMC  
{ E36<Wog  
e.printStackTrace (); Y0&w;P  
} X H{5E4P  
u'yePJTE  
v:JFUn}  
return n; nFw&vR/q  
} [EB2o.E sO  
<2}"Y(zwKl  
\<i#Jn+)  
} [GU!],Y  
hL67g  
Y5c( U)R8  
/* .zBSjh_=H  
**SiteInfoBean.java #uuwzE*M_  
*/ cMC1|3  
package NetFox; + #S]uC  
d!Y,i!l!  
<%qbU-  
public class SiteInfoBean { 6CY_8/:zL  
zT!JHG  
c6BaC@2  
private String sSiteURL; //Site's URL hh:0m\@<  
private String sFilePath; //Saved File's Path G]QD6b9~  
private String sFileName; //Saved File's Name >'Y]C\  
private int nSplitter; //Count of Splited Downloading File ;2#7"a^  
Z~T- *1V  
.6e5w1r63  
public SiteInfoBean() n?kU  
{//nSplitter的缺省值为5 He"> kJx  
//default value of nSplitter is 5 1G{$ B^ f  
this("","","",5); Pg*ZQE[ME8  
} rb`C:#j{J  
`4\H'p  
oE-i`;\8  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?>4^e:  
{ L|!9%X0.  
sSiteURL= sURL; al#yc  
sFilePath = sPath; K'1rS[^>R  
sFileName = sName; PuUqWW'^  
this.nSplitter = nSpiltter; ;M@ /AAZ  
KZ/}Iy>As  
I#uJdV|x  
} 7Py8!  
ew }C*4qH  
G>*s+  
public String getSSiteURL() Er~5\9,/<]  
{ BuK82   
return sSiteURL; |`:Uww+3  
} 2&Wc4,O!i  
lFI"U^xC  
?\ho9nyK  
public void setSSiteURL(String value) E*rDwTd  
{ 2\EMtR>.M'  
sSiteURL = value; 2E=E!Zwt_  
} h2h$UZIv  
N:"E%:wSbi  
G} }oeS  
public String getSFilePath() Q:=s99  
{ RFQa9Rxk  
return sFilePath; Dve5Ml-  
} ?A,gDk/#  
<<4G GO  
`|v0@-'$  
public void setSFilePath(String value) o8Q(,P  
{ GW.s\8w  
sFilePath = value; n# Z6d`  
} \*d@_oQ$  
Ha4?I$'$  
WpSdukXY{  
public String getSFileName() GD~3RnGQ{  
{ {*>$LlL  
return sFileName; pEhWgCL  
} qXP)R/~OZ  
Xo{Ce%L  
|MTgKEsn  
public void setSFileName(String value) <NT/+>:2  
{ J"FKd3~:E  
sFileName = value; _RY<-B   
} KJcdX9x  
>nvreis  
w?<:`  
public int getNSplitter() o.}^6.h"  
{ -"!V&M  
return nSplitter; LF*3Iw|v  
} n1buE1r?  
= eTI@pN`  
sOU_j4M{  
public void setNSplitter(int nCount) hiU_r="*ox  
{ /i DS#l\0  
nSplitter = nCount; `d3S0N6@  
} e0>@Yp[Kd  
} 6sB!m|zm]:  
"%A[%7LY  
|mY<TWoX  
/* ,<pql!B-  
**Utility.java a,&Kvh  
*/ !i}G>*XH,  
package NetFox; |W*f 6F3  
_2f}WY3S  
CdTmL{Y1  
public class Utility { t'm]E2/  
Z4h P  
!jYV,:'  
public Utility() D|9B1>A,m  
{ NF&\<2kX  
a7#Eyw^H{  
?ADk`ts~,}  
} ,ISq7*%F  
{} vl^b  
//线程睡眠 {fIH9+v  
public static void sleep(int nSecond) =bv8W < #  
{ EY2s${26%  
try{ jGt'S{  
Thread.sleep(nSecond); _;LHC;,:  
}  tEP^w  
catch(Exception e) r OB\u|Pg  
{ .=^h@C*   
e.printStackTrace (); z^B!-FcIz>  
} QfwGf,0p  
} &Lq @af#  
:nZ*x=aq  
//日志 3t%uUkXl  
public static void log(String sMsg) }$ AC0  
{ O8dDoP\F2  
System.err.println(sMsg); lD C74g  
} /=7|FtB`  
eTrGFe!8w  
xZ9y*Gv\=  
public static void log(int sMsg) *+@/:$|U  
{ g3x192f  
System.err.println(sMsg); DO( /,A<{8  
} U35}0NT _  
} @ju-cv+  
.v;2Q7X  
p}(w"?2  
/* * ?KQ\ Y  
**TestMethod.java sBSBDjk[  
*/ ={feN L  
package NetFox; F1%' zsv  
ih~c(&n0  
bWMM[pnL  
public class TestMethod { ao7|8[  
\=5CNe  
:;??!V  
public TestMethod() OpH9sBnA  
{ ///xx/weblogic60b2_win.exe `yC R.3+  
try{ RKBjrSZg8  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Yn I   
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y?5*K  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9sT?"(=  
fileFetch.start(); Wm3H6o*  
} 1p8E!c{}j  
catch(Exception e){e.printStackTrace ();} 5'z&kl0"S  
/!%P7F  
K7_)!=DcX  
} C %EQ9Iq6r  
W}.4$f>  
$6'xRUx X  
public static void main(String[] args) S?8q.59  
{ ,#"AWQ  
new TestMethod(); !J:DBtGT  
} ?T4%"0  
} {b#c0>.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
欢迎提供真实交流,考虑发帖者的感受
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八