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
  • 10308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
/* 3bu VU& ap  
**SiteFileFetch.java [94A?pn[z  
*/ ;U<;R  
package NetFox; Q}d6+C  
import java.io.*; $Lv,e\]  
import java.net.*; 7f#e#_sM;  
>K1)XP  
RmY5/IYR|:  
public class SiteFileFetch extends Thread { b %L8mX  
'U.)f@L#w  
<w` R ;  
SiteInfoBean siteInfoBean = null; //文件信息Bean 21bvSK  
long[] nStartPos; //开始位置 aB0L]i  
long[] nEndPos; //结束位置 _d 76jmujJ  
FileSplitterFetch[] fileSplitterFetch; //子线程对象  msM  
long nFileLength; //文件长度 "6 |j 0?Q  
boolean bFirst = true; //是否第一次取文件 S3EY9:^ C  
boolean bStop = false; //停止标志 _?M34&.X  
File tmpFile; //文件下载的临时信息 6x)7=_:0  
DataOutputStream output; //输出到文件的输出流 P{i\x#  
M' e<\wqm  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Hgu$)yhlj  
public SiteFileFetch(SiteInfoBean bean) throws IOException f <fa +fB  
{ %B}Q.'  
siteInfoBean = bean; ~ P"@^cq  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); C=IT`iom1C  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); &YGd!Q  
if(tmpFile.exists ()) ;e4 15T  
{ \,ARYwd  
bFirst = false; i#Io;  
read_nPos(); m~'!  
} Q [kbEhv;  
else NQz*P.q  
{ JGOry \  
nStartPos = new long[bean.getNSplitter()]; ,Md8A`7x~  
nEndPos = new long[bean.getNSplitter()]; $wg5q\Rv  
} N4I`6uDgD  
nICc}U?k  
B>rz<bPT  
zsFzF`[k  
} xHq"1Vs=  
}(A`aB_  
y G)xsY V  
public void run() [Ul"I-K  
{ H C(Vu  
//获得文件长度 T\I}s"d  
//分割文件 3)88B"E  
//实例FileSplitterFetch ~U(`XvR\4  
//启动FileSplitterFetch线程 3O7]~5 j1  
//等待子线程返回 pYf57u  
try{ S[J eW  
if(bFirst) 3u#bx1  
{ U$v|c%6  
nFileLength = getFileSize(); CuC1s>  
if(nFileLength == -1)  a?S5 =  
{ ^MIF+/bQ  
System.err.println("File Length is not known!"); N;4bEcWjp  
} #V&98 F  
else if(nFileLength == -2) 3.@"GS#"[  
{ =!)Ye:\Q  
System.err.println("File is not access!"); )UbPG`x8  
} TwlX'iI_;  
else 7'Z-VO  
{ YbtsJ <w  
for(int i=0;i<nStartPos.length;i++) g xY6M4  
{ 0`c|ZzY  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); VK*Dm:G0  
} waI?X2  
for(int i=0;i<nEndPos.length-1;i++) 86Hg?!<i.  
{ .a2b&}/.d  
nEndPos = nStartPos[i+1]; F] e` -;  
} 2 j.6  
nEndPos[nEndPos.length-1] = nFileLength; %jk7JDvl  
} 7irpD7P>  
} Lh%z2 5t  
v+Eub;m   
@~k4,dJ  
//启动子线程 ,1/O2aQ%\0  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Zc9@G-  
for(int i=0;i<nStartPos.length;i++) oC ?UGY~xL  
{ } I>68dS[  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m}A|W[p<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TOapq9B]  
nStartPos,nEndPos,i); GT.1,E ,Vw  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6&| hpp#[  
fileSplitterFetch.start(); #1*#3p9UL  
} [wU e"{  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R!i\-C1 S  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V=^B7a.;>  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U\*]cw  
nEndPos = " + nFileLength); VyX5MVh  
// fileSplitterFetch[nPos.length-1].start(); 6$CwH!42F  
Jq>rA  
Z$ ?(~ln  
//等待子线程结束 F+o4f3N  
//int count = 0; %,T=|5  
//是否结束while循环 M[  {O%!  
boolean breakWhile = false; WC0z'N({W  
Kb X&E0  
-t]3 gCLb  
while(!bStop) m`i_O0T  
{ 88Nx/:#Y*  
write_nPos(); @)#EZQix  
Utility.sleep(500); YRg"{[+#]k  
breakWhile = true; <O Y (y#x  
yFoPCA86y  
$%BI8_  
for(int i=0;i<nStartPos.length;i++) <W] RyEg`  
{ Ri>4:V3K  
if(!fileSplitterFetch.bDownOver) nTsKJX%\  
{ Pi+pQFz5  
breakWhile = false; "C0?s7Y  
break; wZ4w`|'  
} R [ZY;g:p  
} rn^cajO^  
if(breakWhile) )]}G8A  
break; 9?X8H1  
FKZ'6KM&A  
yPrF2@#XZ/  
//count++; 6am g*=]  
//if(count>4) _'8P8 T&  
// siteStop(); 5P Zzaz<  
} E5aRTDLq  
K;z$~;F  
(E;+E\E  
System.err.println("文件下载结束!"); Ez8k.]qu  
} *+OS;R1<  
catch(Exception e){e.printStackTrace ();} c@3mfc{  
} =yF]#>Ah  
:V3z`}Rl  
{Qi J-[q  
//获得文件长度 :)Pj()Os|  
public long getFileSize() N0DzFXp  
{ H )51J:4  
int nFileLength = -1; Y5CDdn  
try{ XGuxd  
URL url = new URL(siteInfoBean.getSSiteURL()); l-Be5?|{_  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GO?hB4 9T  
httpConnection.setRequestProperty("User-Agent","NetFox"); _aeIK  
.k:heN2-x  
l+#J oc<8  
int responseCode=httpConnection.getResponseCode(); 0iYo&q'n  
if(responseCode>=400) _01wRsm%2  
{ ;6eBfMhL  
processErrorCode(responseCode); jme`Tyd  
return -2; //-2 represent access is error 0~~yYo&  
} T;G<62`.h  
wz'=  
xa.tH)R  
String sHeader; Ul_ 5"3ze  
#M%K82"  
0G31Kou  
for(int i=1;;i++) &szYa-K*  
{ V/3@iOwD  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7u{V1_ n1  
//Utility.log(in.readLine()); ^Q6?T(%$  
sHeader=httpConnection.getHeaderFieldKey(i); WBD?|Ss  
if(sHeader!=null) He,, bq  
{ e)= " Fq!  
if(sHeader.equals("Content-Length")) ZNVrja*  
{ Sn S$5o  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ZIKSHC9  
break; %x.du9  
} ]1FLG* sB  
} 0 N"N$f  
else 'W,*mfB  
break; j7U&a}(  
} 1fvN[  
} PB *v45  
catch(IOException e){e.printStackTrace ();} e|?eY)_  
catch(Exception e){e.printStackTrace ();} 2eHVl.C5  
qu1+.z=|  
Uks%Mo9on  
Utility.log(nFileLength); h%U}Y5Ps~  
3.@LAF  
5 w(nttYH  
return nFileLength; HKr}"`I.  
} 43x2BW&&  
RC}m]!Uz  
w3ATsIw  
//保存下载信息(文件指针位置) _p>F43%p  
private void write_nPos() O wuc9  
{ &r.M~k >  
try{ ; PncJe5x  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9dw* ++  
output.writeInt(nStartPos.length); KF6C=,Yc%  
for(int i=0;i<nStartPos.length;i++) p^|6 /b  
{ wZZ~!"O &  
// output.writeLong(nPos); N8pV[\f  
output.writeLong(fileSplitterFetch.nStartPos); ,f{w@Er  
output.writeLong(fileSplitterFetch.nEndPos); HMC-^4\%[  
}  =n5n  
output.close(); t7l{^d_L  
} 5F+G8  
catch(IOException e){e.printStackTrace ();} T60pw  
catch(Exception e){e.printStackTrace ();} jz`3xFy *]  
} y=c={Qz@vn  
gyMHC{l/B  
S2DG=hi`GK  
//读取保存的下载信息(文件指针位置) 67hfve  
private void read_nPos() gROK4'j6y  
{ ;p2b^q'  
try{ WQ 2{`'z  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); % YK xdp  
int nCount = input.readInt(); )=sbrCl,C/  
nStartPos = new long[nCount]; =6qTz3t  
nEndPos = new long[nCount]; xL1Li]fM!'  
for(int i=0;i<nStartPos.length;i++) S.4+tf 7+  
{ iMt3h8  
nStartPos = input.readLong(); rrr_{d/  
nEndPos = input.readLong(); {g#4E0.A!  
} H0#=oJr$)W  
input.close(); 4uzMO<  
} {aNpk,n  
catch(IOException e){e.printStackTrace ();} R|}N"J_  
catch(Exception e){e.printStackTrace ();} g0bYO!gC r  
} gs;^SRE I  
0Dna+V/jI  
J,:&U wkv  
private void processErrorCode(int nErrorCode) y] c1x=x  
{ hVmnXT 3Z  
System.err.println("Error Code : " + nErrorCode); t"Ci1"U  
} En1LGi4#  
u -P !2vT  
RYA@{.O  
//停止文件下载 !b7"K|  
public void siteStop() }dop]{RG  
{ Y*$>d/E  
bStop = true; I-Z|FKh_C  
for(int i=0;i<nStartPos.length;i++) R2n 2mQ<  
fileSplitterFetch.splitterStop(); g\fj6  
\7i_2|w  
/ZD6pF  
} =$Mf:F@  
} }mXYS|{  
//负责部分文件的抓取 QOo'Iv+EL  
**FileSplitterFetch.java 'St6a*  
*/ ) PTvw>  
package NetFox; ZaU8eg7  
^t5My[R  
>9rZV NMU  
import java.io.*; ?9a%g\`?:  
import java.net.*; F^'$%XKV  
^L5-2;s<U'  
3q}j"x?  
public class FileSplitterFetch extends Thread { fCx (  
\OA{&G.  
VO8rd>b4  
String sURL; //File URL jOVF+9M  
long nStartPos; //File Snippet Start Position EC;>-s  
long nEndPos; //File Snippet End Position Cp(2]Eb  
int nThreadID; //Thread's ID Z.Yq)\it  
boolean bDownOver = false; //Downing is over ]vlBYAW'  
boolean bStop = false; //Stop identical ey=KAt  
FileAccessI fileAccessI = null; //File Access interface X0u,QSt' O  
q50F!yHC-  
2^=.j2  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3}<U'%sd  
{ W\k8f+Ke  
this.sURL = sURL; LXK!4(xaW  
this.nStartPos = nStart; 8s$6R|ti  
this.nEndPos = nEnd; |g)C `k  
nThreadID = id; /T)E&=Ds  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /7 Tm2Vj8  
} PQkw)D<n]_  
az6 &  
Zt!A!Afu  
public void run() Os@b8V 8,A  
{ Fs(PVN  
while(nStartPos < nEndPos && !bStop) nf/?7~3?[  
{ b/'c h  
ZrTB%  
X+aQ 7^"s  
try{ = 'NV3by  
URL url = new URL(sURL); hr}f5Z)^v  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^;RK-)  
httpConnection.setRequestProperty("User-Agent","NetFox"); 80*hi)ux[  
String sProperty = "bytes="+nStartPos+"-"; b& +zAt.  
httpConnection.setRequestProperty("RANGE",sProperty); \~l_w ,Poo  
Utility.log(sProperty); w!7ApEH1  
@|SeabN^-  
(c(F1=K  
InputStream input = httpConnection.getInputStream(); ZpVkgX4  
//logResponseHead(httpConnection); rk W7;!  
5, 1<A@H  
0cq@lT6  
byte[] b = new byte[1024]; .how@>:P+  
int nRead; 93HVx#  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (QiA5!wg  
{ +gX,r$bX  
nStartPos += fileAccessI.write(b,0,nRead); L'e^D|  
//if(nThreadID == 1) &/? Ct!_  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +:.Jl:fx4  
} =EP`,zqn$9  
{h@\C|nF  
c4Zpt%:}h  
Utility.log("Thread " + nThreadID + " is over!"); K:a8}w>Up  
bDownOver = true; sQa;l]O:NC  
//nPos = fileAccessI.write (b,0,nRead); [34N/;5  
} JcR|{9ghT  
catch(Exception e){e.printStackTrace ();} xmv %O&0^}  
} LpU}.  
} HU $"o6ap  
;o!p9MEpz;  
T;/GHC`{Y  
//打印回应的头信息 |#@7$#j  
public void logResponseHead(HttpURLConnection con) U=.PL\  
{ G;l7,1;MU:  
for(int i=1;;i++)  v_!6S|  
{ z%YNZ ^d  
String header=con.getHeaderFieldKey(i); B$_4 ul\)  
if(header!=null) ,x8;| o5  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I9S;t _Z<  
Utility.log(header+" : "+con.getHeaderField(header)); OOqT0w N  
else J:m/s9r  
break; JXK\mah  
} X&pYLm72;  
} N `|A  
'Rn-SD~gIr  
EL?(D  
public void splitterStop() 'QCIKCn<  
{ :5NMgR.d  
bStop = true; /I`TN5~  
} 6h;(b2p{  
8)X9abC  
c* {6T}VZr  
} r(>S  
KNx/1 lf  
m^D'p  
/* DXLXGvcM  
**FileAccess.java :<qe2Z5k  
*//文件访问(定位,写) *,\"}x*  
package NetFox; @V%\Gspv  
import java.io.*; qT$k%(  
c@t?R$c  
_Je 4&KU  
public class FileAccessI implements Serializable{ }%_|k^t  
Zhq_ pus"a  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $D^\[^S  
RandomAccessFile oSavedFile; IOl_J>D]F  
long nPos; TEC^|U`G  
0\dmp'j]  
.EKlw##  
public FileAccessI() throws IOException M~:_^B  
{ KZppQ0  
this("",0); ?"x4u#x  
} C}8#yAS9M  
b(*\4n  
J2=4%#R!  
public FileAccessI(String sName,long nPos) throws IOException E\[BE<y  
{ 3oCI1>k  
oSavedFile = new RandomAccessFile(sName,"rw"); o1.~g'!^  
this.nPos = nPos; 4D?h}U /  
oSavedFile.seek(nPos); !mNst$-H4  
} 24jf`1XFW  
W0gS>L_  
I=0c\ U}  
public synchronized int write(byte[] b,int nStart,int nLen) \OwF!~&  
{ 9M96$i`P  
int n = -1; @{y'_fw  
try{ &6x(%o|  
oSavedFile.write(b,nStart,nLen); '}Fe&%  
n = nLen; yfG;OnkZ  
} 46:<[0Psl/  
catch(IOException e) u H[WlZ4  
{ aCG rS{  
e.printStackTrace (); +4?Lwp'q  
} {iD/0q  
<]rayUyaf  
l/N<'T_G  
return n; NL9.J @"b  
} ?v2_7x&  
/q9I^ztV  
A,~3oQV  
} B7 %,D}  
FuHBzBoM=  
\*$^}8  
/* >]h{[kU %4  
**SiteInfoBean.java 51k}LH  
*/ d0aXA+S%  
package NetFox; Qte5E}V`  
=g#PP@X]D!  
hG1$YE  
public class SiteInfoBean { bY~K)j v3&  
?qjdmB|w  
OgF[=  
private String sSiteURL; //Site's URL CD`a-]6qA  
private String sFilePath; //Saved File's Path HMq}){=S  
private String sFileName; //Saved File's Name [DaAvN^0A  
private int nSplitter; //Count of Splited Downloading File Q0J1"*P0  
kF|$oBQ  
m%|\AZBA#  
public SiteInfoBean() z9o]);dZ  
{//nSplitter的缺省值为5 >dAl*T  
//default value of nSplitter is 5 IK -vcG  
this("","","",5); {<-s&%/r  
} :\;9y3  
\Id8X`,eD  
b<a3Ue%  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mA(kq   
{ 8SjCU+V  
sSiteURL= sURL; UFB|IeX?q  
sFilePath = sPath; YgEd%Z%4  
sFileName = sName;  /~"-q  
this.nSplitter = nSpiltter; .eJKIck  
Vl5r~+$|  
Igo`\JY  
} %xgP*%Sv2  
.O- )m'5  
5Q10Ohh  
public String getSSiteURL() ZX_QnSNZ?  
{ Q7+WV`&  
return sSiteURL; KMhrw s{&B  
} s\*p|vc  
$xu2ZBK  
Zo=,!@q(  
public void setSSiteURL(String value) Ab$E@H #  
{ UynGG@P@  
sSiteURL = value; A;U c&G  
} QYA4C1h'  
#(] D]f[@  
?1\5X<|,  
public String getSFilePath() k5RzW4zq;  
{ SzLlJUVX  
return sFilePath; HYl+xH'.j  
} %pZT3dcK  
"@x( 2(Y&  
i;HXz`vT7  
public void setSFilePath(String value) SqAz((  
{ (u?s@/e:`/  
sFilePath = value; 5H._Q  
} 6C$+D  
I gJu/{:y^  
o#FctM'Z  
public String getSFileName() |]kiH^Ap  
{ W 8<QgpV*  
return sFileName; ,.Gp_BI  
} ir^d7CV,   
h#zm+([B*  
i}T* | P  
public void setSFileName(String value) 5zS%F: 3  
{ M.g2y&8  
sFileName = value; DS8HSSD  
} 2?,l r2  
dwn|1%D  
8i6iynR  
public int getNSplitter() c<1$ zQY!  
{ t_/qd9Jv  
return nSplitter; o9sQ!gptw  
} GVT 6cR  
!MSa -  
i%yKyfD  
public void setNSplitter(int nCount) n[/D>Pi  
{ Yte*$cJ=  
nSplitter = nCount; ( %sf wv  
} thPAD+u.3  
} %Vo'\|  
$Y/z+ea  
2K~v`c*4  
/* XzAXcxC6G  
**Utility.java pll5m7[  
*/ Z{3=.z{&^=  
package NetFox; y95  #t  
eHx {[J?  
 o]0E  
public class Utility { .Z 7t E?  
 !5 S#  
DvWBvs,  
public Utility() _~Lu%   
{ |TJ gH<I  
[?z;'O}y  
['(qeS@5O  
} 6X ]I`e  
eI|FrBq%  
//线程睡眠 z{.&sr>+v  
public static void sleep(int nSecond) D*L@I@ [  
{ nR%w5oe  
try{ ?r;F'%N=  
Thread.sleep(nSecond); K*~xy bA  
} c'$y_]  
catch(Exception e) 8?~>FLWTXZ  
{ SP0ueAa}  
e.printStackTrace (); ^C,rN;mX'  
} FUI/ A >  
} Tu:lIy~A  
ruhC:rg:/  
//日志 Fkv284,LM  
public static void log(String sMsg) W&A^.% 2l  
{ + fvVora  
System.err.println(sMsg); S?DMeZ{:  
} 89[/UxM)  
i{g~u<DH)Q  
oKRI2ni$j9  
public static void log(int sMsg) k8Dk;N  
{ QKk7"2t|  
System.err.println(sMsg); ,9OER!$y  
} N#J8 4i;ry  
} l2#~   
6hcs )X7m  
#E4oq9{0*W  
/* ^g'uR@uU  
**TestMethod.java N]BH67<  
*/  w&U28"i>  
package NetFox; :hHKm|1FE  
UeUOGf ,  
Na\&}GSf^  
public class TestMethod { jcePSps]  
Jcvp<  
$hM9{  
public TestMethod() Kd}%%L  
{ ///xx/weblogic60b2_win.exe .Sm 8t$  
try{ z#5qI',L  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {s@&3i?ZiC  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5);  LWo)x  
SiteFileFetch fileFetch = new SiteFileFetch(bean); JpQV7}$  
fileFetch.start(); lfoPFJ Z  
} 8yr-X!eF  
catch(Exception e){e.printStackTrace ();} tjZS:@3 Z  
r*7J#M /  
NR^Z#BU  
} &sq q+&ao  
c:DV8'fT  
<95*z @  
public static void main(String[] args) +C$wkx]  
{ ZU:c[`  
new TestMethod(); V" 5rIk  
} 4YMUkwh  
} R<T5lkJ\/  
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
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八