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http断点续传简单实现(java)

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/* f7a"}.D $  
**SiteFileFetch.java A9WOu*G1O  
*/ ~iIFe+6  
package NetFox; W6)XMl}n  
import java.io.*; DB'3h7T  
import java.net.*; c],Zw  
,!^g8zO  
MIu'OJ"z~  
public class SiteFileFetch extends Thread { R0yp9icS  
_$mS=G(  
]'vAeC6{  
SiteInfoBean siteInfoBean = null; //文件信息Bean k#2b3}(,  
long[] nStartPos; //开始位置 `uc`vkVZ  
long[] nEndPos; //结束位置 eH9-GGr  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 QZ5%nJme_  
long nFileLength; //文件长度 FC4hvO(/m  
boolean bFirst = true; //是否第一次取文件 qvs[Gkaa@  
boolean bStop = false; //停止标志 IFXnGDG$  
File tmpFile; //文件下载的临时信息 e63io0g>  
DataOutputStream output; //输出到文件的输出流 U9Lo0K  
vX*kvEG  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 9Z:pss@  
public SiteFileFetch(SiteInfoBean bean) throws IOException ?'$} k  
{ S+pm@~xe  
siteInfoBean = bean; rD>q/,X=\  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ^Uldyv/  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); _2<k,Dl;RY  
if(tmpFile.exists ()) c- [IgX e  
{ K14{c1  
bFirst = false; 602=qb  
read_nPos(); 5?TjuGc  
} %Gjjl*`E  
else ks8xxY  
{ F'55BY*!  
nStartPos = new long[bean.getNSplitter()]; ([hd  
nEndPos = new long[bean.getNSplitter()]; |H8UT S X+  
} qjRp5  
Z-i$KF  
a]x\e{  
Csm23QLsg)  
} FFc?Av?_  
z\<gm$1CB  
$t>ow~Xi  
public void run() rzKn5Z  
{ a@-!,Hi  
//获得文件长度 e)4L}a  
//分割文件 jAD{?/RB}  
//实例FileSplitterFetch HF%)ip+  
//启动FileSplitterFetch线程 'L6+B1Op  
//等待子线程返回 PLWx'N-kqL  
try{ <-|g>  
if(bFirst) M5B?`mTl  
{ i^/D_L.  
nFileLength = getFileSize(); zQx7qx  
if(nFileLength == -1) WtbOm  
{ cs)z!  
System.err.println("File Length is not known!"); I\VC2U  
} ACH!Gw~  
else if(nFileLength == -2) y/ah<Y0(  
{ RTYhgq  
System.err.println("File is not access!"); x;/%`gKn8  
} W.<I:q`eO  
else J]Qbg7|  
{ [M:BJ%*  
for(int i=0;i<nStartPos.length;i++) !%YV0O0  
{ :;Wh!8+j  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); "cX*GTNi8  
} V, e  
for(int i=0;i<nEndPos.length-1;i++) p:qj.ukw  
{ j=w`%nh4"f  
nEndPos = nStartPos[i+1]; qo0]7m7|  
} QLyBP!X-  
nEndPos[nEndPos.length-1] = nFileLength; PF-"^2&_  
} ON$-g_s>)  
} Z65]|  
&M+fb4:_  
_6'HBE  
//启动子线程 _qhYG1t  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CFx$r_!~  
for(int i=0;i<nStartPos.length;i++) W_G'wU3R  
{ lmr:PX  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \YsYOFc|  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6V c&g  
nStartPos,nEndPos,i); TWJ%? /d  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?1MaA  
fileSplitterFetch.start(); v]BMET[w  
} 4O3-PU>N  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gR) )K)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6\?< :Qto  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n>I NJ  
nEndPos = " + nFileLength); xn 4-^2  
// fileSplitterFetch[nPos.length-1].start(); hlTM<E  
_cH 7lO[  
Tg.}rNA4  
//等待子线程结束 626 !6E;T  
//int count = 0; i9k/X&V  
//是否结束while循环 .TetN}w  
boolean breakWhile = false; q/yL={H?  
Sf*b{6lcC  
Gd%E337d  
while(!bStop) nc.X+dx:  
{ _8"%nV  
write_nPos(); qU,u(El  
Utility.sleep(500); 6'qC *r   
breakWhile = true; m%km@G$  
>~k"C,6  
YV>]c9!q  
for(int i=0;i<nStartPos.length;i++) X Sw0t8  
{ 2N:|BO>  
if(!fileSplitterFetch.bDownOver) cp>1b8l6?  
{ Q'S"$^~{  
breakWhile = false; k\a&4v  
break; r+%}XS%;h  
} X,8 ]g.<  
} :;]iUjiC8  
if(breakWhile) lZ9rB^!  
break; P>3 ;M'KsO  
vmZyvJSE  
0? QTi(  
//count++; /^<Uy3F[p  
//if(count>4) [q{[Avqf  
// siteStop(); S( r Fa  
} u4a(AB>S  
mxJ& IV  
qE&R.I!o  
System.err.println("文件下载结束!"); |[}!E/7>b  
} yk| < P\  
catch(Exception e){e.printStackTrace ();} fSFb)+  
} <wZ2S3RNA  
N3J;_=<4  
|B;tv#mKD  
//获得文件长度 Ma,2_oq+  
public long getFileSize() ]V K%6PQ0  
{ .`3O4]N[  
int nFileLength = -1; e1 j3X\ \  
try{ u 6(O;  
URL url = new URL(siteInfoBean.getSSiteURL()); (}u2) 9  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]l WEdf+  
httpConnection.setRequestProperty("User-Agent","NetFox"); vC9Qe ]f  
$ RDwy)9  
s8/y|HN^  
int responseCode=httpConnection.getResponseCode(); ;NHZD  
if(responseCode>=400) ;L458fYs  
{ T!*lTzNHm  
processErrorCode(responseCode); Z4 +6'  
return -2; //-2 represent access is error k_hV.CV  
} $R2iSu{kO  
yIL6Sb  
z_^Vgb]  
String sHeader; MM*B.y~TxZ  
.A. VOf_  
As;@T$G  
for(int i=1;;i++) 5QR=$?K  
{ zMf .  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vO#=]J8`  
//Utility.log(in.readLine()); L:ox$RU  
sHeader=httpConnection.getHeaderFieldKey(i); $6ev K~  
if(sHeader!=null) /uM;g9 m  
{  ju-tx :  
if(sHeader.equals("Content-Length")) )oRF/Xx`g  
{ B8Cic\2  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kIlc$:K^  
break; 1@)kNg)*$  
}  M[^  
} ueyz@{On~  
else Mbua!m(0  
break; /Jjub3>Q  
} %)$^_4.g  
} i*We kr3Wo  
catch(IOException e){e.printStackTrace ();} ur,!-t(~t  
catch(Exception e){e.printStackTrace ();} {WE1^&Vk-}  
V kA$T8  
[!ghI%VK  
Utility.log(nFileLength); wsnR$FhQ`  
aeQvIob@  
h2SVDKj  
return nFileLength; 9Q<8DMX^  
} WPmH4L>T  
K\7\  
[<+A?M=  
//保存下载信息(文件指针位置) 5v f?E"\r  
private void write_nPos() fZqqU|tq  
{ !y&uK&1  
try{ }Ss]/ _t  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;wi}6rF%[i  
output.writeInt(nStartPos.length); zq=X;}qYj  
for(int i=0;i<nStartPos.length;i++) ZH:-.2*cj  
{ mUmU_L u8  
// output.writeLong(nPos); [\ M$a|K  
output.writeLong(fileSplitterFetch.nStartPos); s[ ze8:  
output.writeLong(fileSplitterFetch.nEndPos); yM *-e m  
} @%7IZg;P6  
output.close(); H\Y5Fd9)  
} ?*36&Iq}  
catch(IOException e){e.printStackTrace ();} WU wH W  
catch(Exception e){e.printStackTrace ();} []'gIF  
} 8!~8:?6n  
4&}V3"lg  
H]6i1j  
//读取保存的下载信息(文件指针位置) 2qw-:  
private void read_nPos() ''{REFjK7  
{ vr,8i7*0  
try{ `OL@@`'^{S  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xu4C*]A>  
int nCount = input.readInt(); g>m)|o'  
nStartPos = new long[nCount]; B}PT-S1l  
nEndPos = new long[nCount]; "$->nC.  
for(int i=0;i<nStartPos.length;i++) wx a?.  
{ u3"0K['3  
nStartPos = input.readLong(); S_E-H.d"  
nEndPos = input.readLong(); 0Jz5i4B  
} oNyVRH ZH  
input.close(); 7,MDFO{n  
} [1-1^JY  
catch(IOException e){e.printStackTrace ();} w1aev  
catch(Exception e){e.printStackTrace ();} }e7os0;s  
} o$*aAgS+  
gx-ib/_f1  
,g.*Mx`-  
private void processErrorCode(int nErrorCode) 'pCZx9 *c  
{ |[/<[@\''  
System.err.println("Error Code : " + nErrorCode); {:D8@jb[  
} {XHAQ9'  
PTU_<\  
V`/ E$a1&  
//停止文件下载 qc(R /[  
public void siteStop() C 2f=9n/  
{ p#5U[@TK  
bStop = true; O_9M /[<  
for(int i=0;i<nStartPos.length;i++) 9g7d:zG  
fileSplitterFetch.splitterStop(); BHVC&F*>  
y&ZyThqg  
B3+9G,or  
} $+ z 3  
} Q]JWWKt6rV  
//负责部分文件的抓取 hA6   
**FileSplitterFetch.java (E{>L).~  
*/ `!`g&:Y  
package NetFox; R`[jkJrc  
''bh{ .x  
DFgQ1:6[  
import java.io.*; ?Uq;>  
import java.net.*; z\d{A7  
8 #m,TOp  
\dm5Em/  
public class FileSplitterFetch extends Thread { prHM}n{0  
s+tPHftp  
.3X5~OH  
String sURL; //File URL CIxa" MW  
long nStartPos; //File Snippet Start Position e=>:(^CS   
long nEndPos; //File Snippet End Position 1@dB*Jt  
int nThreadID; //Thread's ID ^(j}'p,  
boolean bDownOver = false; //Downing is over )8cb @N  
boolean bStop = false; //Stop identical K nl`[Nl  
FileAccessI fileAccessI = null; //File Access interface `"(FWK=8)"  
l}bAwJ?  
"QKCZ8_C  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException og`rsl  
{ &$$o=Yg,  
this.sURL = sURL; _>8rTk`/h  
this.nStartPos = nStart; Ulf'gD4e  
this.nEndPos = nEnd; r}**^"mFy  
nThreadID = id; H*m3i;"4p\  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t@&U2JaL>W  
} %O69A$Q[m  
l&/V4V-  
NmuzAZr  
public void run() L@5j? N?F  
{ (-no`j  
while(nStartPos < nEndPos && !bStop) Dru iiA  
{ 9{GEq@`7  
x>cl$41!W  
_xefFy  
try{ o=nF.y  
URL url = new URL(sURL); }T5 E^  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ybkydc  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;p(I0X  
String sProperty = "bytes="+nStartPos+"-"; g@O H,h/  
httpConnection.setRequestProperty("RANGE",sProperty); `SH14A*  
Utility.log(sProperty); W ZT) LYA  
z/I\hC9i  
&-$27  
InputStream input = httpConnection.getInputStream(); 7D KTd^^M  
//logResponseHead(httpConnection); V0<g$,W=  
68UfuC  
;/h&40&  
byte[] b = new byte[1024]; xZ]QT3U+  
int nRead; -U{CWn3G  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !X[P)/?b0+  
{ ]#\De73K   
nStartPos += fileAccessI.write(b,0,nRead); O**~ Tj  
//if(nThreadID == 1) uq2C|=M-x\  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *N |ak =  
} GGs7]mhA  
j"s7P%  
rJT YCe1*  
Utility.log("Thread " + nThreadID + " is over!"); Y3 \EX  
bDownOver = true; :jf/$]p  
//nPos = fileAccessI.write (b,0,nRead); .k-t5d  
} b/w5K2  
catch(Exception e){e.printStackTrace ();} I&6M{,rnM  
} Q!!u=}GYK  
} @#p6C  
rEMe=>^   
' Tk4P{  
//打印回应的头信息 /iEQ}  
public void logResponseHead(HttpURLConnection con) z1^3~U$}  
{ v5 @9  
for(int i=1;;i++) D<`M<:nq  
{ f5Hv![x  
String header=con.getHeaderFieldKey(i);  sd"eu  
if(header!=null) X`(fJ',  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lWn}afI  
Utility.log(header+" : "+con.getHeaderField(header)); ^?2zoS#iw  
else w!pj);jy{  
break; '5b0 K1$"  
} {r~=mQ  
} ify48]  
lCgzQZ  
B]NcY&A  
public void splitterStop() ZWni5uF-c  
{ |2=@8_am  
bStop = true; 5UJ ?1"J  
} tLU@&NY`  
$)  M2  
%JH/|mA&|  
} &8pGq./lr=  
t Davp:M1v  
%gQUog  
/* NJSbS<O  
**FileAccess.java w?zy/+N~  
*//文件访问(定位,写) Bd 0oA )i  
package NetFox; &Nh zEl1  
import java.io.*; P*B @it  
aOw#]pB|  
LEOri=?RF  
public class FileAccessI implements Serializable{ x[$KZGK+GL  
$f _C~O  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9XYm8g'X  
RandomAccessFile oSavedFile; ce#Iu#qT  
long nPos; xAl8e  
.zl[nx[9"D  
F:d2;  
public FileAccessI() throws IOException zy%0;%  
{ B'Jf&v  
this("",0); 4:S]n19nq  
} &ds+9A  
xJAQ'ANr  
kI9I{ &J&  
public FileAccessI(String sName,long nPos) throws IOException }!{R;,5/n  
{ \<(EV,m2  
oSavedFile = new RandomAccessFile(sName,"rw"); n$XEazUb0N  
this.nPos = nPos; :4-,Ru1C"  
oSavedFile.seek(nPos); +Adk1N8  
} ^ >&#F[aT  
@C!&lrf3  
NP\mzlI~@  
public synchronized int write(byte[] b,int nStart,int nLen) 5jso)`IL  
{ X.S<",a{qz  
int n = -1; LGW:+c  
try{ pW@W-k:u  
oSavedFile.write(b,nStart,nLen); -.y1]4  
n = nLen; [|YvVA  
} SD:D8"8  
catch(IOException e) b9#(I~}  
{ kW2DKr-[  
e.printStackTrace (); zwU[!i)  
} Tg"? TZO~  
?}v/)hjp=?  
99`w'Nlk  
return n; {d*OJ/4  
} _Y ;tD  
Ihf)gfHj  
B @QWr;  
} Su7N?X!  
LEeA ,Y  
= c Z24I  
/* d5>&, {o7N  
**SiteInfoBean.java 1KrJS(.  
*/ akt7rnt?i  
package NetFox; hrq% {!Z  
m7y[Y  
=]-z?O6^`  
public class SiteInfoBean { ye=4<b_  
A-:k4] {%P  
KpYezdPF)  
private String sSiteURL; //Site's URL @XolFOL"f"  
private String sFilePath; //Saved File's Path `_1~[t  
private String sFileName; //Saved File's Name CEI"p2  
private int nSplitter; //Count of Splited Downloading File * 30K}&T  
O=V_ 7I5  
RqGX(Iuv  
public SiteInfoBean() aVHIU3  
{//nSplitter的缺省值为5 ^~-YS-.J#,  
//default value of nSplitter is 5 te2vv]W1  
this("","","",5); KcpYHWCa.  
} >h\u[I$7  
Lo_+W1+  
xx>h J!  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C 'MR=/sd  
{ 'nGUm[vh  
sSiteURL= sURL; ,lA @C2 c  
sFilePath = sPath; OqIXFX"  
sFileName = sName; eK l; T  
this.nSplitter = nSpiltter; 3m!tb)  
5v)bs\x6  
iLZY6?_^  
} Ms,MXJtH  
dt:$:,"   
a{r"$>0  
public String getSSiteURL() r9&m^,U  
{ yD7}  
return sSiteURL; kMurNA=  
} O 7 aLW  
V=*^C+6s  
5Y^"&h[/  
public void setSSiteURL(String value) :K]7(y7>  
{ FMeBsI9pL  
sSiteURL = value; Wj^e)2%  
} El5} f4sl  
K2yNI q_  
cbyzZ#WRb  
public String getSFilePath() p9?kJKN  
{ ^@AyC"K  
return sFilePath; -)oUb=Lk{  
} [,Go*r  
]/1\.<uJId  
#l4T/`u'9!  
public void setSFilePath(String value) |EX=Rj*  
{ }q@#M8b  
sFilePath = value; i,*m(C@F}  
} 9;U?_   
t kj  
Y /_CPY  
public String getSFileName() dREY m}1  
{ 3r kcIVO  
return sFileName; sd\p[MXX  
} q/U-6A[0  
$xZ ~bE9  
Icrnu}pl_  
public void setSFileName(String value) N7J?S~x  
{ 8^ f:-5  
sFileName = value; {:uv}4Z  
} )e?&'wa>  
lUs$I{2_  
j0mN4Ny  
public int getNSplitter() i)|jLrW~e  
{ 6EyPZ{  
return nSplitter; ZK^cG'^2|  
} &}k7iaO  
X>o9mW  
7:u+cv  
public void setNSplitter(int nCount) )/::i O&$:  
{ j %gd:-tA  
nSplitter = nCount; +,>%Yb =EA  
} 0W*{ 1W  
} U*$P"sS`  
xrg?{*\  
Y)X7*iTi'j  
/* E@ U]k$M  
**Utility.java bJ!\eI%ld  
*/ JyMk @Y  
package NetFox; M/Yr0"%Q<.  
+`Z1L\gmA  
NAvR^"I~  
public class Utility { !|&|%x6@  
*tF~CG$r  
wL?Up>fr  
public Utility() v&YeQC>  
{ #%p44%W  
c,2& -T}  
Lkm-<  
} tf~B,?  
w_56y8Pd4  
//线程睡眠 Kt_oo[ey{  
public static void sleep(int nSecond) +r8bGS]ki  
{ &*<27-x  
try{ A ]A{HEX  
Thread.sleep(nSecond); ^r\ rpSN  
} JkAM:,^(  
catch(Exception e) sg $db62>  
{ yv[j Pbe  
e.printStackTrace (); }UW7py!TN  
} luf5-XT  
} g^]Iw~T6$  
XX~vg>3_  
//日志 ':wf%_Iw  
public static void log(String sMsg) c 3QgX4vq  
{ VyxYv-$Y  
System.err.println(sMsg); 1XSnnkJm  
} s7 "xDDV  
x"12$7 9=  
:]-oo*xP  
public static void log(int sMsg) sW]^YT>?  
{ -XV,r<''  
System.err.println(sMsg); +'?Qph6o,7  
} | ;tH?E  
} /sKL|]i=  
l/X_CM8y~  
o{s2T)2  
/* [MTd<@  
**TestMethod.java !LN8=u.  
*/ tUv>1) [  
package NetFox; >D,Oav  
xPm. TPj  
=:WZV8@%  
public class TestMethod { 8v"rM >[  
ebk>e*  
EU?qLj':  
public TestMethod() {[o NUzcd  
{ ///xx/weblogic60b2_win.exe ff#7}9_mh  
try{ \Z]+j@9  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nj[TTnd Jt  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `>:5[Y  
SiteFileFetch fileFetch = new SiteFileFetch(bean); \HeJc:^  
fileFetch.start(); h&<"jCjL  
} $xbC^ k  
catch(Exception e){e.printStackTrace ();} 9pp +<c  
;28d7e}  
*r`=hNr  
} v/`D0g-uX)  
(u,)v_Oo]a  
x%B_v^^^  
public static void main(String[] args) ?Z#N9Z~\  
{ OsgPNy0  
new TestMethod(); !Z!)$3bB  
} *d 1Bp R%  
} kt6x"'"1  
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