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
  • 12182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
/* j@Y'>3  
**SiteFileFetch.java P] qL&_  
*/ LAU\.d  
package NetFox; 1t<  nm)  
import java.io.*; |)b:@q3k+n  
import java.net.*; lD@`xq.M;  
;&ypvKG  
)LjW=;(b  
public class SiteFileFetch extends Thread { pij%u<  
.5GGZfJ]  
|,WP)  
SiteInfoBean siteInfoBean = null; //文件信息Bean ,*d<hBGbh  
long[] nStartPos; //开始位置 {*AYhZ  
long[] nEndPos; //结束位置 \jHIjFwQ  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 w ;xbQZ|+  
long nFileLength; //文件长度 m53~Ysq<  
boolean bFirst = true; //是否第一次取文件 d9.~W5^fC  
boolean bStop = false; //停止标志 m-MfFEZ  
File tmpFile; //文件下载的临时信息 "aJf W  
DataOutputStream output; //输出到文件的输出流 Q;0 g  
3\0,>L9ET@  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) @XN|R  
public SiteFileFetch(SiteInfoBean bean) throws IOException M|}V6F_y  
{ L<[%tvV  
siteInfoBean = bean; y5`$Aa4~  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 9; `E,w  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); <@J0 770  
if(tmpFile.exists ()) HCZVvsG  
{ G)3Q|Vc  
bFirst = false; P|QM0GI  
read_nPos(); 4~Jg\@  
} + vO; J  
else /DoSU>%hK  
{ 9 1ndr@*|  
nStartPos = new long[bean.getNSplitter()]; c^x5 E`{  
nEndPos = new long[bean.getNSplitter()]; @"O|[%7e  
} gfly?)VnF  
c, FZ{O@  
0artR~*}  
g& ?{^4t]  
} l$g \t]  
TWSx9ii!M:  
5 =Op%  
public void run() 5LJ0V  
{ qcGsx2  
//获得文件长度 -DL"Yw}  
//分割文件 dd:vQOF;  
//实例FileSplitterFetch ZXC_kmBN/  
//启动FileSplitterFetch线程 MWJ}  
//等待子线程返回 e^yfoE<7  
try{ b&2 N7%  
if(bFirst) _Z_R\  
{ j kV9$W0  
nFileLength = getFileSize(); I T?~`vi  
if(nFileLength == -1) );=0cnr3  
{ s |!lw  
System.err.println("File Length is not known!"); lAJ P X  
} jAak,[~;  
else if(nFileLength == -2) *IWWD\U  
{ 1w'W)x  
System.err.println("File is not access!"); 6\vaR#  
} yz^4TqJ  
else *~Sv\L  
{ SGK 5  
for(int i=0;i<nStartPos.length;i++) =;~*YD(%/  
{ #R*7y%cO  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ?(Ytc)   
} H_FT%`iM  
for(int i=0;i<nEndPos.length-1;i++) ob]j1gYb  
{ UM:]Qba In  
nEndPos = nStartPos[i+1]; tX~ *.W:  
} *NCkC ~4  
nEndPos[nEndPos.length-1] = nFileLength; R^&.:;Wi>  
} 2"IDz01ne  
} \Sv8c}8  
@Io@1[kj  
'9@AhiNV  
//启动子线程 #T++5G  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K8RV=3MBLD  
for(int i=0;i<nStartPos.length;i++) l- $5CO  
{ U<I]_]  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t 09-y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?.^n,[2  
nStartPos,nEndPos,i); tP4z#0r2  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9xaieR  
fileSplitterFetch.start(); REWW(.3o  
} ;L[N.ZY!  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q#zU0K*^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^X ~S}MX  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ti!kJ"q  
nEndPos = " + nFileLength); 2B b,ZC*  
// fileSplitterFetch[nPos.length-1].start(); Hq#q4Y  
]DjnzClx  
Scfe6+\EW  
//等待子线程结束 $ D.*r*c6  
//int count = 0; E?S  
//是否结束while循环 m\G45%m  
boolean breakWhile = false; 0( q:K6zI}  
)3.=)?XW  
|cgc^S/~H  
while(!bStop) {$Z S 2 7  
{ Tly*i"[&  
write_nPos(); SvQ!n4 $  
Utility.sleep(500); *yYeqm  
breakWhile = true; 8(g}/%1mt3  
p# JPLCs  
';xp+,'}\  
for(int i=0;i<nStartPos.length;i++) #=N6[:,  
{ @6b4YV h  
if(!fileSplitterFetch.bDownOver) uc aa;zj  
{ eh}|Wd7J  
breakWhile = false; B*:W`}G]_c  
break; iX-.mq$  
} m= rMx]k  
} q\xsXM  
if(breakWhile) Zs2;VW4RW  
break; ]z8Th5a?o  
'&/~Sh$%  
|_OoD9,M  
//count++; %LBf'iA  
//if(count>4) }kSP p  
// siteStop(); ndu$N$7+  
} b8**M'k  
%E[ $np>  
8ib e#jlg  
System.err.println("文件下载结束!"); |? rO  
} g%okYH?  
catch(Exception e){e.printStackTrace ();} Pq1j  
} Ml6}47n  
'EC0|IT)c  
a fLE9  
//获得文件长度 s9SUj^  
public long getFileSize() baGV]=j  
{ `jec|i@oO  
int nFileLength = -1; u)vS,dzu  
try{ IZuP{7p$  
URL url = new URL(siteInfoBean.getSSiteURL()); +I+RNXR/{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C!Jy;Z=+u  
httpConnection.setRequestProperty("User-Agent","NetFox"); \+"Jg/)ij  
5xQ5)B4k  
WO$8j2!~#  
int responseCode=httpConnection.getResponseCode(); F`>qg2wO  
if(responseCode>=400) x"A\ Z-xxz  
{ = u&dU'@q  
processErrorCode(responseCode); f9t+x+ Z  
return -2; //-2 represent access is error I#;.; %u  
} 3gYtu-1  
<?h(Dchq  
1n[wk'}qf4  
String sHeader; a:s$[+'Y  
@ 6*eS+t\  
3zv0Nwb,  
for(int i=1;;i++) *;T'=u_lR  
{ &5*t*tI  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *Ag3qnY  
//Utility.log(in.readLine()); uK0L>  
sHeader=httpConnection.getHeaderFieldKey(i); qp{~OW3  
if(sHeader!=null) nfh<3v|kvR  
{ !QC ErE;r  
if(sHeader.equals("Content-Length")) h6?o)Q>N  
{ pZ]&M@Ijp  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <) -]'@*c  
break; ~MP/[,j`  
} EqOhzII^  
} loUZD=Ph  
else Oj8D+sC{  
break; $`P]%I}  
} :lu"14  
} bI8')a  
catch(IOException e){e.printStackTrace ();} #mD_<@@  
catch(Exception e){e.printStackTrace ();} ?rziKT5OOC  
}{mS"  
%vbov}R  
Utility.log(nFileLength); _+Z5qUmQ  
!wC( ]Y  
/T 2 v`Li  
return nFileLength; ExF6y#Y G<  
} h@J3+u<  
nELY(z  
BU|)lU5)z  
//保存下载信息(文件指针位置) PP]7_h^ 2  
private void write_nPos() C3~O6<,Jh  
{ &UO/p/a  
try{ 93 =?^  
output = new DataOutputStream(new FileOutputStream(tmpFile)); V."cmtf  
output.writeInt(nStartPos.length); v=cX.^ L  
for(int i=0;i<nStartPos.length;i++) ~du U& \  
{ zjSHa'9*  
// output.writeLong(nPos); 5mZwg(si  
output.writeLong(fileSplitterFetch.nStartPos); CZ>Ujw=&k  
output.writeLong(fileSplitterFetch.nEndPos); qRz /$|.  
} ( X+2vN  
output.close(); S;oRE' kk  
} J&B5Ll  
catch(IOException e){e.printStackTrace ();} I9x kqj  
catch(Exception e){e.printStackTrace ();} F I~=A/:  
} +G+1B6S  
7Hj7b:3K&!  
 bDD29  
//读取保存的下载信息(文件指针位置) NC iB n>=:  
private void read_nPos() Tl#2w=  
{ TD78&a#  
try{ jvpv1>KYV  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F+L%Ho;@P  
int nCount = input.readInt(); . g-  HB'  
nStartPos = new long[nCount]; }}bMq.Q'  
nEndPos = new long[nCount]; = J]M#6N0  
for(int i=0;i<nStartPos.length;i++) 9W-1P}e,  
{ 8"p rWAN  
nStartPos = input.readLong(); |:,`dQfw  
nEndPos = input.readLong(); /lhk} y^  
} 4J?\JcGs  
input.close(); /2MZH  
} 8~T=p:z'  
catch(IOException e){e.printStackTrace ();} tY:,9eh7B  
catch(Exception e){e.printStackTrace ();} _xBhMu2f  
} Aj(y]p8  
4UK>Vzn  
:Ys ;)W+R  
private void processErrorCode(int nErrorCode) X":2o|R  
{ d= ?lPEzSA  
System.err.println("Error Code : " + nErrorCode); D(WV k  
} Nq|y\3]  
SR_ -wD  
Tt=;of{  
//停止文件下载 m"6K_4r]  
public void siteStop() p#3G=FV  
{  m3^D~4  
bStop = true; IkxoW:L  
for(int i=0;i<nStartPos.length;i++) `$FB[Z} &  
fileSplitterFetch.splitterStop(); DghqSL ^s  
=NSunW!  
Zv* uUe  
} AYfe_Dj  
} s,l*=<  
//负责部分文件的抓取 BuUM~k&SY  
**FileSplitterFetch.java T0.sL9  
*/ P>^$X  
package NetFox; "z= ~7g  
t:xTmK&vt  
8 qZbsZi4  
import java.io.*; =k;X}/  
import java.net.*; OMd:#cWsQ  
^(@]5$^Z  
MBnxF^c&P  
public class FileSplitterFetch extends Thread { /LtbmV  
C5jt(!pi  
4W<[& )7  
String sURL; //File URL 7#X`D  
long nStartPos; //File Snippet Start Position [Z&<# -  
long nEndPos; //File Snippet End Position Zq H-]?)  
int nThreadID; //Thread's ID t:v>W8N53  
boolean bDownOver = false; //Downing is over 2izBB,# "  
boolean bStop = false; //Stop identical M@p<L VP  
FileAccessI fileAccessI = null; //File Access interface ?6L8#"=  
9e}%2,  
d`% 7Pk  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b! teSf  
{ [57`V &c5  
this.sURL = sURL; x<@i3Y{[  
this.nStartPos = nStart; 7]i6 Gk  
this.nEndPos = nEnd; 8dJ+Ei~M  
nThreadID = id; T)Q_dF.N  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "L8Hgwg  
} Ekh)l0 l  
G({VK  
N P5K1:  
public void run() .q!i +0  
{ H+@?K6{h  
while(nStartPos < nEndPos && !bStop) jl>wvY||  
{ /b/  6*&  
Og?GYe^_  
%?F$3YN,  
try{ ^+gD;a|t  
URL url = new URL(sURL); : #so"O  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Zv?"1Y< L  
httpConnection.setRequestProperty("User-Agent","NetFox"); y{~tMpo<  
String sProperty = "bytes="+nStartPos+"-"; I|;C} lfp  
httpConnection.setRequestProperty("RANGE",sProperty); W7{^/s5r  
Utility.log(sProperty); B|{E[]iK  
oZdY0nh4  
(E~6fb "c  
InputStream input = httpConnection.getInputStream(); ZS`Kj(D  
//logResponseHead(httpConnection); QIJ/'72  
i [Wxu M  
{XD':2E  
byte[] b = new byte[1024]; D=Yr/qc?  
int nRead; Fq%NY8KNE  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +8"P*z,  
{ bQPO'S4  
nStartPos += fileAccessI.write(b,0,nRead); (m=1yj9  
//if(nThreadID == 1)  -rT#Wi  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2^nws  
} ][YuJUK8  
{M= *>P]E  
mX?t|:[b  
Utility.log("Thread " + nThreadID + " is over!"); XN{zl*`  
bDownOver = true; a:4!z;2 |  
//nPos = fileAccessI.write (b,0,nRead); i CB:p  
} 4Y4zBD=<  
catch(Exception e){e.printStackTrace ();} @RL'pKab9  
} u:B=lZ[  
} &5[+p{2  
E]S:F3  
K$r)^K=s  
//打印回应的头信息 .YP&E1lNi  
public void logResponseHead(HttpURLConnection con) 73SH[f[g  
{ {.DY\;Q  
for(int i=1;;i++) ^+k= ;nl  
{ [$:L| V!{  
String header=con.getHeaderFieldKey(i); ]Zc\si3i&  
if(header!=null) nwqA\  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xVN!w\0  
Utility.log(header+" : "+con.getHeaderField(header)); {+3g*s/HI  
else C@<gCMj,"  
break; #7}YSfm^6  
} xr7M#n  
} F[W0gjUc  
z+CX$.Z  
<:mK&qu f  
public void splitterStop() <(yAat$H  
{ ;:>q;%  
bStop = true; <P@O{Xi+K  
} ! CJ*zZ*  
nHp(,'R/  
H$pgzNL  
} ?IoA;GBg  
mZuLwd$0  
,WM-%2z^4I  
/* lvNi/jk  
**FileAccess.java Pv3G?u=4  
*//文件访问(定位,写) S/RChg_L5  
package NetFox; (Jk[%_b>_  
import java.io.*; b)E<b{'W  
FN (O  
Ww#!-,*]o  
public class FileAccessI implements Serializable{ 'C#[iRG4  
wjgFe]  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \'iy(8i  
RandomAccessFile oSavedFile; ]!a?Lr  
long nPos; 9wO2`e )  
/Nob S'd  
fL]jk1.Xv-  
public FileAccessI() throws IOException ?,%PemN  
{ whrDw1>(  
this("",0); BN FYUcVP  
} S_RP& +!7  
'fk6]&-I  
gr{*wYL  
public FileAccessI(String sName,long nPos) throws IOException NA`8 ^PZ  
{ g-NrxyTBlx  
oSavedFile = new RandomAccessFile(sName,"rw"); ra_v+HR7  
this.nPos = nPos; j'hWhLax  
oSavedFile.seek(nPos); %T\ 2.vl  
} J8Vzf$t};  
 acQHqR  
*Tr{a_{~C  
public synchronized int write(byte[] b,int nStart,int nLen) 8F's9c,  
{ } j;es(~D  
int n = -1; mG0_&'"YIG  
try{ L .}sN.  
oSavedFile.write(b,nStart,nLen); "*(a2k3J  
n = nLen; ~ t N/  
} BglbQ'6p  
catch(IOException e) {y%@1q%"  
{ 5@I/+D  
e.printStackTrace (); % I2JS  
} gFfKK`)}D'  
\ Z5160  
v-Q>I5D;:  
return n; $+Z2q<UT  
} )e6sg]#  
wwJs_f\  
j#Lj<jX!xR  
} FP*kA_z$  
FT-=^VA\  
9RkNRB)8  
/* t)~$p#NS  
**SiteInfoBean.java 9- 24c  
*/ ZA@zs,o%  
package NetFox; o=xMaA  
m@0> =s~.  
t=s.w(3t  
public class SiteInfoBean { ziM@@$ .F  
kmtkh "  
Z5EII[=$o  
private String sSiteURL; //Site's URL ^gR~~t;@  
private String sFilePath; //Saved File's Path ;lhW6;oI'  
private String sFileName; //Saved File's Name P6=5:-Hh  
private int nSplitter; //Count of Splited Downloading File ^),t=!;p  
YRd`G3J  
>RpMw!NT  
public SiteInfoBean() k72NXagh  
{//nSplitter的缺省值为5 :C,}DyZy  
//default value of nSplitter is 5 'Z#>K*  
this("","","",5); _u6MSRX[6$  
} iU3PlF[B/o  
e#F3KLSL`  
%[azMlp<  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *!3qO^b?  
{ c>+68<H  
sSiteURL= sURL; ,pQ[e$u1  
sFilePath = sPath; 7m?fv Ky  
sFileName = sName; >}JEX]V  
this.nSplitter = nSpiltter; }LLQ +  
5 [4{1v  
4nh0bIN1  
} HYY+Fv5  
Q|2*V1"r<2  
[6/8O  
public String getSSiteURL() NZFUCD)  
{ :()K2<E  
return sSiteURL; OIjG`~Rx  
} L&uPNcZ`-  
_?$w8 S%  
0(&Rm R  
public void setSSiteURL(String value) a( N;| <  
{ @uG/2'B(  
sSiteURL = value; ;z+}|>!  
} 78?cCj{e  
j8rxhToC  
Vh]=sd<F  
public String getSFilePath() X gtn}7N.  
{ L;+e)I]  
return sFilePath; CUBL/U\=  
} + [$Td%6  
jyidNPLm4  
t2rZ%[O  
public void setSFilePath(String value) r@wE?hK  
{ &4l!2  
sFilePath = value; [MKt\(  
} }h8U.k?v  
0 wDhX  
w]V684[>  
public String getSFileName() G9K& }_,  
{ 8H8Q  
return sFileName; \]\h,Y8  
} K2V?[O#  
t?=V<Yd1  
lEb H4 g  
public void setSFileName(String value) $~?)E;S  
{ e:_[0#  
sFileName = value; mmCGIX  
} EZ hk(LE  
mGoC8t}iP  
mD*!<<Sw  
public int getNSplitter() yD8Qy+6L  
{ \{ C ~B;=  
return nSplitter; q^<;B Y  
} .G"T;w 6d  
Mi F( &#  
WE-+WC!!:  
public void setNSplitter(int nCount) w7vQ6jkH  
{ [=u@6Y  
nSplitter = nCount; 0}T 56aD=!  
} k ,r*xt  
} s t#^pWL  
r|/9'{!  
qQ,(O5$|  
/* dwiLu&]u  
**Utility.java Gvr>n@n  
*/ '] _7Xa'  
package NetFox; t_(S e  
t$R0UprK  
.E{FD%U  
public class Utility { DQ0 UY  
GpR,n2  
%%h.`p1  
public Utility() `/WOP`'zM  
{ 2+R]q35-  
$:onKxVM  
*GdJ<B$  
} %0 U@k!lP  
3jto$_3'w  
//线程睡眠 FR]uCH  
public static void sleep(int nSecond) %Rk0sfLvn  
{ 2o W'B^-  
try{ tlI]);iE,  
Thread.sleep(nSecond); *ODc[k'(  
} <UGM/+aO  
catch(Exception e) ygUX]*m!  
{ !L/.[:X  
e.printStackTrace (); (+BrC`  
} 7&L8zl|K  
} "ZmxHMf  
+]hc!s8  
//日志 jDj=a->e^  
public static void log(String sMsg) >: J1Gc  
{ EFu>  
System.err.println(sMsg); tM;+U  
} vJ&35nF&  
hIa,PZ/Q  
H3Zt 3l1u+  
public static void log(int sMsg) 1Eryw~,,9i  
{ a<((\c_8G  
System.err.println(sMsg); *;lb<uLv  
} xz7CnW1  
} F^=y+}]=  
jo0XOs  
i/C0 (!  
/* -}8r1jQH;  
**TestMethod.java e >7Ka\  
*/ G2:.8 ok  
package NetFox; vQDR;T"]  
@Qqf4 h  
CwO$EL:[`  
public class TestMethod { )>;387'Y  
CKU)wJ5t  
S@4bpnhK  
public TestMethod() |(Xxi  
{ ///xx/weblogic60b2_win.exe .Lm`v0' w  
try{ c-Qa0 Q  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i}))6   
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _e|-O>#pl  
SiteFileFetch fileFetch = new SiteFileFetch(bean); B5;94YIN  
fileFetch.start(); eYv+tjIF  
} clIn}wQ  
catch(Exception e){e.printStackTrace ();} X{h[    
I7<UC{Ny  
;N _ %O  
} 9HlM0qE5b  
M IUB]  
;;EFiaA  
public static void main(String[] args) owO &[D/  
{ p\]rxtm  
new TestMethod(); 1}CJ&  
} SNHAL F  
} P>|sCF  
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 或 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