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http断点续传简单实现(java)

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/* J*} warf&  
**SiteFileFetch.java U'(@?]2 <G  
*/ awic9 uMH  
package NetFox; BQ7p<{G  
import java.io.*; H ]x-s  
import java.net.*; %P2l@}?a  
= olmBXn/  
5m]N%{<jAB  
public class SiteFileFetch extends Thread { iir]M`A.-  
<_N<L\  
Z/f%$~Ch  
SiteInfoBean siteInfoBean = null; //文件信息Bean <+mYC'p  
long[] nStartPos; //开始位置 _sGmkJi]  
long[] nEndPos; //结束位置 DZ7<-SFU  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 @z-%:J/$  
long nFileLength; //文件长度 Q`kJ3b   
boolean bFirst = true; //是否第一次取文件 v?=y9lEH@%  
boolean bStop = false; //停止标志 #oX8EMqs<  
File tmpFile; //文件下载的临时信息 i=^!? i  
DataOutputStream output; //输出到文件的输出流 J )DFH~p  
il5Qo  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) DQy<!Wb+  
public SiteFileFetch(SiteInfoBean bean) throws IOException bk}'wcX<+]  
{ 4,]z  
siteInfoBean = bean; {%b*4x0?  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); zv8AvNDK  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); [PW\l+i  
if(tmpFile.exists ()) %A^V@0K3  
{ ac%6eW0#  
bFirst = false; 7B)m/%>3s  
read_nPos(); 1R+/T  
} FP_q?=~rFs  
else 8h%oJ4da   
{ 4Nun-(q  
nStartPos = new long[bean.getNSplitter()]; _ / >JM0  
nEndPos = new long[bean.getNSplitter()]; 6B=: P3Y  
} h7"c_=w+  
j*' +f~ A  
p"UdD  
L<62-+e`  
} _*m<Z;Et  
l3O!{&~K  
<1%(%KdN[  
public void run() 9k.5'#  
{ };Oyv7D+b  
//获得文件长度 z *FCd6X  
//分割文件 aJ/}ID  
//实例FileSplitterFetch E;tEmGf6F  
//启动FileSplitterFetch线程 y2{uEbA  
//等待子线程返回 fFYfb4o  
try{ "!w#E6gU  
if(bFirst) $~+(si2  
{ a-bj! Rs  
nFileLength = getFileSize(); p.^qB]%  
if(nFileLength == -1) `]7==c #Y  
{ ?bH&F  
System.err.println("File Length is not known!"); )4MM>Q  
} u _mtdB'  
else if(nFileLength == -2) 0;Oe&Y  
{ yCvP-?2  
System.err.println("File is not access!"); |8q:sr_  
} zo| '  
else h4#y'E!,Z  
{ F(?O7z"d  
for(int i=0;i<nStartPos.length;i++) .<Rw16O  
{ qeUT]* w  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 1 ]A$  
} !*1 $j7`tP  
for(int i=0;i<nEndPos.length-1;i++) .C*mDi)wZ  
{ %;eD.If}  
nEndPos = nStartPos[i+1]; -^aJ}[uaI  
} [o"<DP6w  
nEndPos[nEndPos.length-1] = nFileLength; 9$?Sts}6&  
} D 0 O^=v|  
} ) UCc!  
Iz^vt#b  
#soV'SFG  
//启动子线程 bQ3txuha  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [} zzG@g,J  
for(int i=0;i<nStartPos.length;i++) kz\Ss|jl  
{ 7 'q *(v  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ve]hE}o/}  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dfP4SJqq  
nStartPos,nEndPos,i); @9tzk [  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <I#nwoHN  
fileSplitterFetch.start(); sg8[TFX@Z  
} hm*cGYV/  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *\(MG|S  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rez )$  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V1&qgAy~  
nEndPos = " + nFileLength); L</k+a?H!  
// fileSplitterFetch[nPos.length-1].start(); hYht8?6}m  
{vq| 0t\-  
8c\\-{  
//等待子线程结束 M u i\E  
//int count = 0; O joa3  
//是否结束while循环 )_YB8jUR-X  
boolean breakWhile = false; o(k{Ed  
M$48}q+  
ZZn$N-  
while(!bStop) 7 x'2  
{ uOO\!Hqq  
write_nPos(); ysj5/wtO0  
Utility.sleep(500); apOa E7|  
breakWhile = true; Q+oV? S3{  
3=Q:{  
=%B5TBG  
for(int i=0;i<nStartPos.length;i++) 5-hnk' ~  
{ Z)}UCi+/".  
if(!fileSplitterFetch.bDownOver) r7,}"Pl  
{ e\em;GTy  
breakWhile = false; B<Q)z5KK  
break; 0NeIQr1N_  
} *`q?`#1&&.  
} : eCeJ~&E  
if(breakWhile) Sv_Nb>  
break; 0|Xz-Y  
=C2KHNc  
vc :%  
//count++; /&c2O X|Z  
//if(count>4) g#MLA5%=u  
// siteStop(); o1vK2V  
} 5X f]j=_  
;I&XG  
j4<K0-?  
System.err.println("文件下载结束!"); Xhq7)/jp  
} NS65F7<&  
catch(Exception e){e.printStackTrace ();} P(3k1SM  
} [#9i@40  
WfD fj  
EV?U !O  
//获得文件长度 T](}jQxj`  
public long getFileSize() R G*Vdom  
{ \BuyJskE  
int nFileLength = -1; ^)wKS]BQ..  
try{ zak|* _  
URL url = new URL(siteInfoBean.getSSiteURL()); a'-u(Bw  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d:k n%L6k_  
httpConnection.setRequestProperty("User-Agent","NetFox"); Wqkzj^;"G  
lYTQg~aPm  
X$;&Mdo.  
int responseCode=httpConnection.getResponseCode(); |his8\C+x  
if(responseCode>=400) B>W8pZu-J  
{ 0-uw3U<  
processErrorCode(responseCode); XZ . T%g  
return -2; //-2 represent access is error _6Y+E"@zs  
} lXg5UrW  
P}]o$nWT  
ESNI$[`  
String sHeader; @ 5^nrB  
-OSj<m<  
^DN:.qQ  
for(int i=1;;i++) 8L,=Eap  
{ FieDESsX>  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >MGWN  
//Utility.log(in.readLine()); c} +*$DeT  
sHeader=httpConnection.getHeaderFieldKey(i); u4_QLf@I  
if(sHeader!=null) 3 3|t5Ia  
{ {"+M%%`*#  
if(sHeader.equals("Content-Length")) PJcfiRa'jQ  
{ s-_D,$ |  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =#/Kg_RKL  
break; m`9nDiV  
} J*[@M*R;&  
} f-G)pHm  
else R0}1:1}$Sn  
break; 59O-"Sc[  
} s(nT7x+W  
} b,^Gj]7  
catch(IOException e){e.printStackTrace ();} J09jBQ] R  
catch(Exception e){e.printStackTrace ();}  kDE-GX"Y  
~\mh\a&  
i1|>JM[V  
Utility.log(nFileLength); +4.s4&f)  
 #D4  
{BmqUoZrC  
return nFileLength; G.H8 ><%  
} T#H^ }`  
!uQT4< g  
^3TNj  
//保存下载信息(文件指针位置) N(Ru/9!y"  
private void write_nPos() ejlns ~  
{ |82q|@e  
try{ 1!KROes4  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~PI2G 9  
output.writeInt(nStartPos.length); E?G'F3i  
for(int i=0;i<nStartPos.length;i++) J7* o%W*V  
{ X58U>4a  
// output.writeLong(nPos); 4%^z=%  
output.writeLong(fileSplitterFetch.nStartPos); {_Wrs.a'8  
output.writeLong(fileSplitterFetch.nEndPos); 755,=U8'wi  
} n&njSj/  
output.close(); W48RZghmx  
} RkE)2q[5  
catch(IOException e){e.printStackTrace ();} Ln4]uqMG.  
catch(Exception e){e.printStackTrace ();} Z^ :_,aJ?  
} `UTPX'Vz  
d/bimQ  
${MzO i  
//读取保存的下载信息(文件指针位置) x-m*p^}  
private void read_nPos() T@tsM|pI  
{ (T_-`N|  
try{ hO]F\0+  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3uocAmY  
int nCount = input.readInt(); z.Ic?Wz7  
nStartPos = new long[nCount]; bGCC?}\  
nEndPos = new long[nCount]; ==OUd6e}  
for(int i=0;i<nStartPos.length;i++) /)6T>/  
{ &t^*0/~  
nStartPos = input.readLong(); -67Z!N  
nEndPos = input.readLong(); UDh \%?j  
} (N}-]%#  
input.close(); ~;3yjO)l?)  
} !?nO0Ao-$  
catch(IOException e){e.printStackTrace ();} KClkPL!jP  
catch(Exception e){e.printStackTrace ();} y#j7vO  
} 4<i#TCGex3  
XI\Slq  
Jh3  
private void processErrorCode(int nErrorCode) P |t yyjO  
{ >$JE!.p%o  
System.err.println("Error Code : " + nErrorCode); C< c6Ub  
} y>EW,%leC  
|%C2 cx  
XM`GK>*aC(  
//停止文件下载 ?$|tT\SFV  
public void siteStop() !0W(f.A{K  
{ `NN P<z+\  
bStop = true; 8Yh'/,o=L#  
for(int i=0;i<nStartPos.length;i++) [)Nt;|U  
fileSplitterFetch.splitterStop(); J<0{3pZY  
9wYm(7M6  
~_fc=^o  
} wa8jr5/k"  
} a9-Mc5^'n  
//负责部分文件的抓取 N1Vj;-  
**FileSplitterFetch.java A0<g8pv  
*/ $@L;j  
package NetFox; k|/VNV( =0  
Wx:v~/r  
I=kqkuW  
import java.io.*; 2Mt$Dah  
import java.net.*; ,Z~`aHhr  
!T,<p    
|*NLWN.ja)  
public class FileSplitterFetch extends Thread { |dgiW"tUm  
~JT`q: l-q  
] 0X|_bU  
String sURL; //File URL wH ,PA:  
long nStartPos; //File Snippet Start Position G}8tFo. d1  
long nEndPos; //File Snippet End Position <D.E .^Y  
int nThreadID; //Thread's ID C}h(WOcr`X  
boolean bDownOver = false; //Downing is over ` IVQ  
boolean bStop = false; //Stop identical z}[ u~P,  
FileAccessI fileAccessI = null; //File Access interface AkQ(V  
R! M'  
rWTaCU^qV  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "du(BZw  
{ m^QoB  
this.sURL = sURL; ^*}D*=>\  
this.nStartPos = nStart; 7Mh'x:p  
this.nEndPos = nEnd; 28"1ONs 3  
nThreadID = id; j2D!=PK;  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f6Y?),`  
} sE?%;uBb  
|HycBTN#E  
OkciL]  
public void run() A;;#]]48  
{ @} r*KF-  
while(nStartPos < nEndPos && !bStop) PaaMh[OmG  
{ Z?+ )ox  
}dN\bb{#  
tx5bmF;b)  
try{ ".>#Qp%  
URL url = new URL(sURL); BQ6$T&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u&l;\w  
httpConnection.setRequestProperty("User-Agent","NetFox"); `,V&@}&"n  
String sProperty = "bytes="+nStartPos+"-"; 6>WkisxG  
httpConnection.setRequestProperty("RANGE",sProperty); jWUrw  
Utility.log(sProperty); 9K& $8aD  
:zU4K=kR  
~!({U nt+'  
InputStream input = httpConnection.getInputStream(); k9 r49lb  
//logResponseHead(httpConnection); c +]r  
I0F [Z\U  
t\/H.Hb  
byte[] b = new byte[1024]; E <yQB39  
int nRead; (d &" @  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1'hpg>U  
{ wo&IVy@s$  
nStartPos += fileAccessI.write(b,0,nRead); 5$U49j  
//if(nThreadID == 1) 0aY|:  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :$G^TD/n  
} &E]) sJ0  
;-1KPDIp`  
JY c:@\   
Utility.log("Thread " + nThreadID + " is over!"); s]m]b#1!r  
bDownOver = true; 12 )  
//nPos = fileAccessI.write (b,0,nRead); rPB Ju0D"  
} q?j7bp]  
catch(Exception e){e.printStackTrace ();} e)H FI|>  
} wf  ]Wm  
} E/H9#  
0")_%  
C/!P&`<6  
//打印回应的头信息 Zg_b(ks  
public void logResponseHead(HttpURLConnection con) \l=A2i7TQ  
{ ikZYc ${  
for(int i=1;;i++) }!K #  
{ gX!K%qJBg  
String header=con.getHeaderFieldKey(i); bmHj)^v 5]  
if(header!=null) A5R"|<UPR  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `m'RvUc  
Utility.log(header+" : "+con.getHeaderField(header)); mCnl@  
else .B^ tEBGVD  
break; ]4O!q}@Cd  
} 3SY1>}(Y  
} y0 vo-Q  
|~76dxU  
I_B%F#X)  
public void splitterStop() @u+LF]MY  
{ z/j*zU `  
bStop = true; /*g0M2+OZo  
} `V/kM0A5  
x<t ?Yc9  
7 :\J2$P  
} pp|$y\ZzB  
6U).vg<  
MZ)lNU l  
/* R Q 8"vF#  
**FileAccess.java x6aVNH=  
*//文件访问(定位,写) Mprn7=I{Tg  
package NetFox; GfgHFv  
import java.io.*; &x (D%+  
rE "FN~9P  
<DMm [V{  
public class FileAccessI implements Serializable{ ]Y,V)41gCE  
0]ai*\,W7~  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 sfVzVS[  
RandomAccessFile oSavedFile; `_&vvJPn@!  
long nPos; 1&h\\&ic  
nVpDjUpN  
wI7.M Gt  
public FileAccessI() throws IOException yTc&C)Jba  
{ Z2;~{$&M+  
this("",0); FS7D  
} >uJu!+#  
3Q&@l49q  
z>W?\[E<2  
public FileAccessI(String sName,long nPos) throws IOException W G3 _(mM  
{ f/ 3'lPK^  
oSavedFile = new RandomAccessFile(sName,"rw"); .mnkV -m  
this.nPos = nPos; 2kgSIvk\  
oSavedFile.seek(nPos); -4Q\FLC'k  
} fda2dY;  
YPs9Pqkn  
:S`12*_g"  
public synchronized int write(byte[] b,int nStart,int nLen) {_>XsB  
{ p>U= Jg  
int n = -1; T2?.o.&u  
try{ G~zfPBN0D  
oSavedFile.write(b,nStart,nLen); _+}o/449  
n = nLen; 2(Xu?W 7d  
} !FK)iQy$0  
catch(IOException e) (R s;+S  
{ &/Gf@[  
e.printStackTrace (); 9r:|u:i7m  
} 3W[||V[r]<  
\0*dKgN  
_+Z;pt$C  
return n; HH3Z?g  
} f4`Nws-dP  
4<EC50@.  
Ga^:y=m  
} "6~+ -_:  
A{3nz DLI  
K6F05h 5S  
/* t[HsqnP  
**SiteInfoBean.java pgUjje>#  
*/ c r18`xU  
package NetFox; IUWJi\,  
PE_JO(e;Xm  
n-?zH:]GG{  
public class SiteInfoBean { ZP:+'\&J  
uxX 3wY;M  
\R 3O39[  
private String sSiteURL; //Site's URL >kuu\  
private String sFilePath; //Saved File's Path iYW<qgz  
private String sFileName; //Saved File's Name `/G9*tIR8g  
private int nSplitter; //Count of Splited Downloading File -lfbn =3  
{rF9[S"h  
}_}LaEYAo  
public SiteInfoBean() c ? Zi/7  
{//nSplitter的缺省值为5 DEPsud;  
//default value of nSplitter is 5 (nkiuCO  
this("","","",5); N7q6pBA"E  
} oB<!U%BN  
qus%?B{b}  
ubKp P%Z  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'v(b^x<ZS  
{ wgQx.8 h>  
sSiteURL= sURL; :VR% I;g;  
sFilePath = sPath; =FAIbM>u  
sFileName = sName; Yru,YA   
this.nSplitter = nSpiltter; *aYuuRx  
6 ZXRb  
#/t+h#jG  
} {XXnMO4uR;  
 ;t/KF"  
$F/xv&t  
public String getSSiteURL() .8|"@  
{ qP9`p4c8i  
return sSiteURL; b$/7rVH!  
} 7$Cv=8  
R_80J=%0  
s?9`dv} P  
public void setSSiteURL(String value) Tkj F /zv  
{ /mn'9=ks  
sSiteURL = value; p8iKZI]g  
} *y~~~ 'J/  
e\ZV^h}TQ  
H@|m^1  
public String getSFilePath() U*BI/wZ  
{ $GD Q1&Z  
return sFilePath; u`*1OqU  
} 0 \1g-kc!v  
%mS>v|  
iML?`%/vN  
public void setSFilePath(String value) 'kJyE9*xU.  
{ K7,Sr1O `  
sFilePath = value; I#(?xHx  
} K:$GmV9o  
3my_Gp  
0.~s>xXp  
public String getSFileName() E,/nK  
{ QwnqysNx4  
return sFileName; U_wIx  
} S;u 2B_/  
-;YhQxxC}L  
h\6 t\_^\  
public void setSFileName(String value) 0<Rq  
{ [mo9?  
sFileName = value; #,SPV&  
} Jn\>S z(96  
N8*QAe kN  
1/=6s5vS}  
public int getNSplitter() e=ry_@7  
{ 0J .]`kR  
return nSplitter; |-]'~ @~  
} k4J Tc2b  
 fTGVG  
.p78 \T  
public void setNSplitter(int nCount) Hr(%y&0  
{ ,H] S-uK~  
nSplitter = nCount; ;(Z9.  
} O}z-g&e.U  
} p-6T,')  
G[zVGqk  
G4EuW *~  
/* e'3y^Vg  
**Utility.java K{iC'^wP  
*/ %\1W0%w  
package NetFox; Y";K WA}b  
!!)NER-dv  
=BO>Bi&&  
public class Utility { C:vVFU|4  
|cl*wFm|3  
/b."d\  
public Utility() 3oPyh $*  
{ 5?>ES*  
>UXNR`?  
`>HrO}x^  
} kq> I?wg  
L1MG("R  
//线程睡眠 =<r1sqf  
public static void sleep(int nSecond) XJA];9^  
{ Z1U@xQj  
try{ I(qFIV+H R  
Thread.sleep(nSecond); CE|rn8MB  
} Lr*\LP6jx3  
catch(Exception e) [$`%ve  
{ }k @S mO8  
e.printStackTrace (); mv#*%St5  
} tPFj[Y~Iy  
} O0sLcuT$  
vSwRj<|CF  
//日志 (~?p`g+I.P  
public static void log(String sMsg) [`!%u3  
{ n"Wlfd0  
System.err.println(sMsg); *~`BG5w  
} Ed1y%mR>  
CWSc#E  
UYhxgPGsj  
public static void log(int sMsg) ZDmY${J  
{  ^]?ju L  
System.err.println(sMsg); R|]n;*y  
} {vp*m :K  
} [G"Va_A8  
5Rae?* XH  
yVyh\u\  
/* pL ,l  
**TestMethod.java yKC1h`2  
*/ 1H8/b D  
package NetFox; Q6xA@"GJ  
[$ z-  
)h0b}HMW)  
public class TestMethod { +77B656  
C40o_1g  
c6VyF=2q  
public TestMethod() )D&xyC}  
{ ///xx/weblogic60b2_win.exe |u+!CR  
try{ HbJ^L:/  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); OU<v9`<  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H`rd bE  
SiteFileFetch fileFetch = new SiteFileFetch(bean); (btm g<WT"  
fileFetch.start(); H4<Q}([w  
} V+t's*9o3  
catch(Exception e){e.printStackTrace ();} l\ Vr D2j8  
$t0JfDd6Ky  
_7'5IA  
}  upGLZ#  
_IWLC{%V  
xcH&B %;f  
public static void main(String[] args) #tA/)Jvi  
{ @I#uv|=N  
new TestMethod(); P+DIo7VTX  
} dj{~!}  
} 0!M'z  
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