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http断点续传简单实现(java)

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/* t*#&y:RG  
**SiteFileFetch.java T}TP.!0E  
*/ ]*h}sn=  
package NetFox; 5b'S~Qj#r$  
import java.io.*; qsRh ihPX  
import java.net.*; Sx"I]N  
iT"Itz-^#  
*)1z-rH`  
public class SiteFileFetch extends Thread { IA4(^-9  
*2MTx   
w1b <>A?87  
SiteInfoBean siteInfoBean = null; //文件信息Bean n58jB:XR(  
long[] nStartPos; //开始位置 SAJ=)h~  
long[] nEndPos; //结束位置 FM)*>ax{  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 C=cTj7Ub  
long nFileLength; //文件长度 ~] 2R+  
boolean bFirst = true; //是否第一次取文件 QAwj]_  
boolean bStop = false; //停止标志 k N+(  
File tmpFile; //文件下载的临时信息 }b(e  
DataOutputStream output; //输出到文件的输出流 J5T#}!f  
LNE[c  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) xTZ5q*Hqx  
public SiteFileFetch(SiteInfoBean bean) throws IOException (I.`bR  
{ >>D i  
siteInfoBean = bean; -EaZ<d[|0  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Hv\*F51p=  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Y c kbc6F  
if(tmpFile.exists ()) L />GYx  
{ POXn6R!mM1  
bFirst = false; h6N}sLM{0  
read_nPos(); "-?Y UY`  
} . 6dT5x8u  
else lz 6 Aj  
{ ^aCYh[=  
nStartPos = new long[bean.getNSplitter()]; WRyLpTr-  
nEndPos = new long[bean.getNSplitter()]; J.l%H U  
} V1`| j  
Qknc.Z}  
zOdKB2_J7  
sD +G+  
} du,-]fF  
y9hZ2iT  
jYz3(mM'J  
public void run() )}!'VIe^!  
{ eb\`)MI/  
//获得文件长度 uek3Y[n  
//分割文件 G |^X:+  
//实例FileSplitterFetch +GU16+w~E  
//启动FileSplitterFetch线程 UD`Z;F  
//等待子线程返回 |/;5|  z  
try{ f:5/y^M&  
if(bFirst) ,?6m"ov4(  
{ u_8 22Z  
nFileLength = getFileSize(); NG UGN~p  
if(nFileLength == -1) {B.]w9  
{ y3]"H(  
System.err.println("File Length is not known!"); %ko 8P  
} mU$7_7V~  
else if(nFileLength == -2) hp4(f W  
{ %Qz`SO8x?  
System.err.println("File is not access!"); #U D  
} DG?\6Zh  
else vP?S0>gh  
{ YO0x68  
for(int i=0;i<nStartPos.length;i++) );DIrA  
{ `kSCH; mwP  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 8]\h^k4f  
} {fv8S;|u  
for(int i=0;i<nEndPos.length-1;i++) FF~4y>R7u  
{ neFno5dj  
nEndPos = nStartPos[i+1]; O Zm[i H  
} D  .R  
nEndPos[nEndPos.length-1] = nFileLength; \#,#_  
} "Cj#bUw  
} ix@rq#  
3uG5b8?  
L.[uMuUa  
//启动子线程  7`@?3?  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0\nhg5]?  
for(int i=0;i<nStartPos.length;i++) \Pmk`^T  
{ )#~fS28j  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %esZ}U   
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (1j$*?iGA  
nStartPos,nEndPos,i); L"6/"L  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $ _Bu,;  
fileSplitterFetch.start(); / i2-h  
} 4(GgaQFO?  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WCTW#<izm  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `Kw8rG\]:  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RmV/wY  
nEndPos = " + nFileLength); nY-9 1q?Y  
// fileSplitterFetch[nPos.length-1].start(); Ytwv=;h-  
3|r!*+.  
p Y>-N  
//等待子线程结束 L)Ar{*xC  
//int count = 0; }QW~.>`  
//是否结束while循环 0a 6z "K}  
boolean breakWhile = false; S_VncTIO  
-f|^}j?  
B2qq C-hw?  
while(!bStop) +u:O AsR  
{ "gajBY  
write_nPos(); FXEfD"  
Utility.sleep(500); #n)W  
breakWhile = true; DLVs>?Y  
[HiTR!o*  
<?7,`P:h[  
for(int i=0;i<nStartPos.length;i++) ||ZufFO  
{ XfK.Fj~-  
if(!fileSplitterFetch.bDownOver) *Q120R  
{ -U;LiO;N  
breakWhile = false; &|"I0|tJ  
break; '!h0![OH  
} (DP9& b  
} MGyB8(  
if(breakWhile) KXA)i5z  
break; l@/kPEh  
aC Lg~g4  
y{I[}$k  
//count++; 8 E+C:"  
//if(count>4) 8Pr7aT:,  
// siteStop(); #L= eK8^e  
} fy>And*  
bok 74U]  
r5da/*G/O  
System.err.println("文件下载结束!"); z/&a\`DsU  
} v[DbhIXU  
catch(Exception e){e.printStackTrace ();} *[~o~e/YCb  
} C5PBfn<j  
nC.2./OwMf  
!v4j`A;%  
//获得文件长度 bKJ7vXC05  
public long getFileSize() yO,`"Dc_0  
{ {r2|fgi  
int nFileLength = -1; zpr@!76  
try{ o"}&qA;  
URL url = new URL(siteInfoBean.getSSiteURL()); n.XhK_6n]M  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4J 51i*`  
httpConnection.setRequestProperty("User-Agent","NetFox"); A1t~&?  
pvQK6r  
HGQ?(2]8$  
int responseCode=httpConnection.getResponseCode(); ^8l3j4  
if(responseCode>=400) C"^hMsU8  
{ X8SRQO^  
processErrorCode(responseCode); r{2].31'  
return -2; //-2 represent access is error V52C,]qQH  
} ie~fQ!rf  
hk!,  
[H:GKhPC`  
String sHeader; sqpOS!]  
, 64t  
]baaOD$Z  
for(int i=1;;i++) 1LId_vJtJ  
{ m_Ac/ct f  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); FJ(B]n[>  
//Utility.log(in.readLine()); oYh<k  
sHeader=httpConnection.getHeaderFieldKey(i); [+MX$y  
if(sHeader!=null) .i&ZT}v3  
{ $K_YC~  
if(sHeader.equals("Content-Length")) |~b R.IA  
{ DMcxa.Sd!  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W aGcoj  
break; X})Imk7&E  
} q&Tn>B  
} H~dHVQtJZ  
else =Wk/q_.  
break; ^g-t#O lD?  
} zIm_7\e  
} J1]w*2  
catch(IOException e){e.printStackTrace ();} N>pmhskN?  
catch(Exception e){e.printStackTrace ();} H1%[\X?=  
g?[& 0r1  
Ph+X{|  
Utility.log(nFileLength); oAZF3h]po  
lHKf#|  
k8 ;uC~L  
return nFileLength; ;64mf`  
} (YYj3#|  
8lWH=kA\  
:9F''f$AP  
//保存下载信息(文件指针位置) m&`(p f4A  
private void write_nPos() qQxA@kdd  
{ bH\C5zt6(  
try{ hP1 l v7P  
output = new DataOutputStream(new FileOutputStream(tmpFile));  Vp] D  
output.writeInt(nStartPos.length); C3\E.u ?  
for(int i=0;i<nStartPos.length;i++) "7yNKO;W  
{ &`yOIX-H_  
// output.writeLong(nPos); 5`E`Kb+@  
output.writeLong(fileSplitterFetch.nStartPos); )v52y8G-p  
output.writeLong(fileSplitterFetch.nEndPos); 4j@i%  
} 5K ,#4EOV  
output.close(); IObx^N_K  
} _}e7L7B7g  
catch(IOException e){e.printStackTrace ();} fzS`dL5,W  
catch(Exception e){e.printStackTrace ();} mGe|8In  
} @1qdd~B}  
9:%n=URd  
`D)Lzm R  
//读取保存的下载信息(文件指针位置) ,]Ro',A&  
private void read_nPos() (/SGT$#8  
{ jWXR__>.  
try{ %0yS98']g  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile));  k6O. H  
int nCount = input.readInt(); I%9bPQ  
nStartPos = new long[nCount]; SY'2A)  
nEndPos = new long[nCount]; x*h?%egB!p  
for(int i=0;i<nStartPos.length;i++) [Y$5zeA  
{ 3duG.iUlL  
nStartPos = input.readLong(); Zn@W7c,_I  
nEndPos = input.readLong(); l@N;sI<O-  
} OQ(D5GR:4  
input.close(); o#xgrMB  
} LZM,QQ  
catch(IOException e){e.printStackTrace ();} !8Z2X!$m{<  
catch(Exception e){e.printStackTrace ();} .73zik   
} hhpv\1h#  
G[3k  
6x_ T@  
private void processErrorCode(int nErrorCode) 8M^wuRn  
{ L6:W'u^  
System.err.println("Error Code : " + nErrorCode); F&QTL-pQW  
} 3ar=1_Ar  
aqs%m (  
{)V?R  
//停止文件下载 >*dQqJI  
public void siteStop() kDzj%sm!  
{ *me,(C  
bStop = true; WY+(]Wkao  
for(int i=0;i<nStartPos.length;i++) LY-lTr@A^  
fileSplitterFetch.splitterStop(); }iilzE4oH#  
"v(G7*2  
a`H\-G  
} B(j02<-  
} 8FzHNG  
//负责部分文件的抓取 ~->Hlxze'K  
**FileSplitterFetch.java _i3i HR?  
*/ tu\mFHvlg  
package NetFox; %won=TG8  
LBiowd[  
m|pTn#*`  
import java.io.*; YC]PN5[1!  
import java.net.*; vd}*_d  
GS\%mPZ  
|9>*$Fe"  
public class FileSplitterFetch extends Thread { ajn-KG!A  
}A{_L6qx  
of9q"h  
String sURL; //File URL "7Eo>g   
long nStartPos; //File Snippet Start Position R? O-x9  
long nEndPos; //File Snippet End Position 8HMo.*Ti9  
int nThreadID; //Thread's ID 3p=vz'  
boolean bDownOver = false; //Downing is over rdO@X9z  
boolean bStop = false; //Stop identical '_B_&is  
FileAccessI fileAccessI = null; //File Access interface ]o-Fi$h!  
7zD- ?%  
* R%.a^R  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6Wj@r!u  
{ JE0?@PI$  
this.sURL = sURL; x6LjcRS|  
this.nStartPos = nStart; KNy`Lj)VPY  
this.nEndPos = nEnd; Hu[]h]  
nThreadID = id; ;}LJh8_  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RfKc{V  
} `f@{Vcr% i  
%drJ p6n%  
ibvJWg  
public void run() {G]?{c)"  
{ Aj,]n>{  
while(nStartPos < nEndPos && !bStop) ],n%Xp  
{ MDk*j,5V  
+%P t_  
JwZ?hc  
try{ TfJL+a0  
URL url = new URL(sURL); OCCEL9d  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EYG"49 c  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;4 ,'y  
String sProperty = "bytes="+nStartPos+"-"; tWm>j  
httpConnection.setRequestProperty("RANGE",sProperty); huz86CO  
Utility.log(sProperty); T?>E{1pS  
PdT83vOCE  
UxyY<H~Wx  
InputStream input = httpConnection.getInputStream(); dY8(nQG  
//logResponseHead(httpConnection); t\8&*(&3F  
C1d 04Q  
'Q5&5UrBr  
byte[] b = new byte[1024]; VBM/x|'  
int nRead; J{d(1gSZ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U R}kB&t  
{ i^WIr h3a  
nStartPos += fileAccessI.write(b,0,nRead); 4IZlUJ?j+c  
//if(nThreadID == 1) )R~aA#<>  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ! ao6e  
} Pey//U  
\<ZLoy_  
{7qA&c=  
Utility.log("Thread " + nThreadID + " is over!"); <s_=-" il  
bDownOver = true; =`-|&  
//nPos = fileAccessI.write (b,0,nRead); =+<d1W`>0  
} u, eZ6  
catch(Exception e){e.printStackTrace ();} #4><r.v3  
} Nsn~@.UuSW  
} b$Ln} <  
fD{II+T  
tjj^O%SV<  
//打印回应的头信息 & 1_U1  
public void logResponseHead(HttpURLConnection con) FPF6H puV  
{ g`n;R  
for(int i=1;;i++) M'q'$)e  
{ G+VD8]!K1  
String header=con.getHeaderFieldKey(i); ]*3:DU  
if(header!=null) "mOI!x f@a  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x` 2| }AP(  
Utility.log(header+" : "+con.getHeaderField(header)); `}gdN};  
else 4=xq:Tf  
break; "b]#MO}P  
} FQROK4x%"  
} o2aM#Q  
94Ud@F9d5  
Hd%! Nt\u  
public void splitterStop() y])).p P  
{ D L{R|3{N  
bStop = true;  / +1{  
} P]Xbjs<p  
1CkdpYjsj  
1 {Jb"  
}  F~6#LT  
j)Y[4 ^k^  
gRAC d&)  
/* ` H XEZ|  
**FileAccess.java e3 v5,.  
*//文件访问(定位,写) vc8?I."?  
package NetFox;  W8]V  
import java.io.*; PK 4`5uT  
'eyJS`  
Km!nM$=k  
public class FileAccessI implements Serializable{ R* 9NR,C  
wAFW*rO5o  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v$Uhm</|19  
RandomAccessFile oSavedFile; `ZMK9f:  
long nPos; 'e@=^FC  
_dU8'H  
26L~X[F  
public FileAccessI() throws IOException MR$>!Nlp  
{ O> c$sL0g  
this("",0); $*\L4<(  
} R?pRxY  
!^y y0`k6  
/YH`4e5g  
public FileAccessI(String sName,long nPos) throws IOException +7U  
{ nX^1$')gp  
oSavedFile = new RandomAccessFile(sName,"rw"); l?8)6z#Zl  
this.nPos = nPos; L9FHgl?  
oSavedFile.seek(nPos); hO#t:WxFI  
} he$XLTmr:  
V*RdDF7  
}T.?c9l X  
public synchronized int write(byte[] b,int nStart,int nLen) ?D|\]0eN  
{ k6(r !mc  
int n = -1; h2w}wsb0l  
try{ C4\,z\Q  
oSavedFile.write(b,nStart,nLen); 9o0!m Cq  
n = nLen; j U[ O  
} ys'T~Cs  
catch(IOException e) @hif$  
{ LA%bq_> f  
e.printStackTrace (); VK:8 Nk_y  
} AIRr{Y  
FT89*C)oD  
.lNs4e  
return n; ! bU\zH  
} Xsuwa-G!5~  
z0bJ?~w,  
@;:>GA  
} gSt`%  
uD9|.P}  
*7$P]  
/* 55Gtp\L  
**SiteInfoBean.java z42F,4Gk  
*/ 7&B$HZ  
package NetFox; &dR=?bz-A  
iv&v8;B  
q,%:h`t\  
public class SiteInfoBean { cz/Q/%j$/  
z[EFQ^*>  
yT8=l"-[G  
private String sSiteURL; //Site's URL +jP~s  
private String sFilePath; //Saved File's Path WYrI|^[>  
private String sFileName; //Saved File's Name 6#e::GD  
private int nSplitter; //Count of Splited Downloading File lfN~A"X  
JC#>Td  
.S?pG_n]f  
public SiteInfoBean() 89~ =eY  
{//nSplitter的缺省值为5 |=dC )Azs  
//default value of nSplitter is 5 f)Xr!7  
this("","","",5); <F=9*.@D   
} 1HT_  
E?)656F[  
mQ~:Y  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W# US#<9Y  
{ Te,$M3|  
sSiteURL= sURL; 9 QC.TG@  
sFilePath = sPath; kA wNly  
sFileName = sName; i38[hQR9a  
this.nSplitter = nSpiltter; [KJ q  
q,>?QBct*  
YDC&u8  
} ZD>a>]  
TX [%(ft  
q MYe{{r  
public String getSSiteURL() 8, "yNq  
{ x_#-tB  
return sSiteURL; LiQgR 6j  
} I5m][~6.?  
~b~2 >c9  
*^%*o?M~  
public void setSSiteURL(String value) zj{r^D$  
{ 2&!bfq![  
sSiteURL = value; .L6Zm U  
} .;7> y7$*  
-O!/Jv"{,[  
rN)V[5R#M  
public String getSFilePath() {a(&J6$VE  
{ "&.S&=FlI  
return sFilePath; 9=X)ung9  
} LE6.nmvS  
^' M>r (t  
q`NXJf=sc  
public void setSFilePath(String value) {'En\e  
{ Q]/Uq~m C  
sFilePath = value; cD|Htt"  
} M<PIeKIEB  
"KX=ow#z|  
IuF_M<d,  
public String getSFileName() Nes=;%&]G  
{ kX`[Y@nUN  
return sFileName; )0 W`  
} 2 {Vcb  
VZ& A%UFC  
'(Gi F  
public void setSFileName(String value) -s|8<A||"  
{ J (4"S o_  
sFileName = value; d?AlI  
} Sq\(pfv o  
NEt1[2X%  
2 dp>Z",  
public int getNSplitter() wr(*?p]R  
{ U6E\AvbRn  
return nSplitter; 0|&\'{  
} 8lF\v/vN  
1NQbl+w#I  
lKWPTCU  
public void setNSplitter(int nCount) ~S,p?I  
{ za Tb~#c_  
nSplitter = nCount; @yd4$Mv8%  
} ]?O2:X  
} @Jm7^;9/  
)a@k]#)Skm  
5tjP6Z`!9`  
/* W&(k!6<x  
**Utility.java !-`Cp3gqHr  
*/ *]hBGr#6  
package NetFox; 7 >iU1zy  
g V5zSudW  
D8&`R  
public class Utility { ,Ys"W x  
3pf[M{dG  
l3Njq^T  
public Utility() y[B>~m8$  
{ HK\~Qnq  
~'37`)]z  
=K'cM=WM6  
} QrO\jAZ{Ag  
cdqB,]"  
//线程睡眠 X\EVTd)@  
public static void sleep(int nSecond) 2(5ebe[  
{ 1f",}qe;  
try{ }_=eT]  
Thread.sleep(nSecond); su*Pk|6%  
} 'lHdOG  
catch(Exception e) (=D&A<YX  
{ lj+u@Z<xA  
e.printStackTrace (); W>-Et7&2  
}  w 4[{2  
} oh# \]c\f  
8-<:i  
//日志 "-@[R  
public static void log(String sMsg) ()&~@1U  
{ }neY<{z  
System.err.println(sMsg); @(r /dZc  
}  hI9  
__mF ?m  
BIuK @$  
public static void log(int sMsg) \%UkSO\nO3  
{  V#VN %{  
System.err.println(sMsg); 87hq{tTs]  
} &0f5:M{P  
} vfVj=DYj  
9z6XF]A  
y;/VB,4V  
/* (o3 Iy  
**TestMethod.java jKt7M>P  
*/ N('&jHF  
package NetFox; n:MdYA5,m  
2eMTxwt*S  
/Q,mJ.CnSR  
public class TestMethod { J:V?EE,\-  
Sa2>`":d  
6{ =\7AY  
public TestMethod() /SYw;<=  
{ ///xx/weblogic60b2_win.exe @)J+,tg/7  
try{ M4as  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;!(<s,c#:  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9 (QJT}qC  
SiteFileFetch fileFetch = new SiteFileFetch(bean); j?'GZ d"B  
fileFetch.start(); .Wjs~0c  
} H;RwO@v  
catch(Exception e){e.printStackTrace ();} "AE5 V'  
Omd .9  
]+X@ 7  
} t.mVO]dsj  
-GxaV #{  
B}^w_C2  
public static void main(String[] args) 4?B\O`sy.  
{ AK@9?_D  
new TestMethod(); c/sC&i;%O  
} dAuJXGo  
} p5G?N(l  
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