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http断点续传简单实现(java)

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/* 4yRT!k}o  
**SiteFileFetch.java \VtCkb  
*/ zXcSE"   
package NetFox; F{l,Tl"Jw  
import java.io.*; ~p'/Z@Atu  
import java.net.*; 'QCvN b6  
s4~c>voQB  
yaR|d3ef?4  
public class SiteFileFetch extends Thread { ^o,@9GT s  
/DbwqBx  
}[AIE[  
SiteInfoBean siteInfoBean = null; //文件信息Bean N1LR _vS"  
long[] nStartPos; //开始位置 XHN?pVZ7  
long[] nEndPos; //结束位置 K<|b>PI.s  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 kZz;l(?0  
long nFileLength; //文件长度 i"JF~6c<  
boolean bFirst = true; //是否第一次取文件 y;<jE.7>  
boolean bStop = false; //停止标志 ]~ec] Y  
File tmpFile; //文件下载的临时信息 ?)]sfJG  
DataOutputStream output; //输出到文件的输出流 '?3Hy|}  
3D<P [.bS  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Em4TEv  
public SiteFileFetch(SiteInfoBean bean) throws IOException Bct>EWQ  
{  sGdt)  
siteInfoBean = bean; '7Te{^<FQ$  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); _9L2JN$R6  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); :&_@U$  
if(tmpFile.exists ()) Xj !0jF33  
{ v+Mt/8  
bFirst = false; : FxZdE  
read_nPos(); uO"@YX/  
} i}HF  
else w'L;`k;Q  
{ &X|z(vSJ$  
nStartPos = new long[bean.getNSplitter()]; F+hsIsQ  
nEndPos = new long[bean.getNSplitter()]; 3*8#cSQ/6o  
} YJ3970c/M  
T*YdGIFO  
nH[@EL  
r43dnwX  
} S;|%'Sn|j9  
}O o  
Q|pz].0  
public void run() &=02.E@  
{ [=V8  
//获得文件长度 D.?KgOZ  
//分割文件 oxGOn('  
//实例FileSplitterFetch -Ep-v4}  
//启动FileSplitterFetch线程 YdeSJ(:  
//等待子线程返回 dX+DE(y  
try{ WBC'~h<@  
if(bFirst) yP-.8[;  
{ >TL0hBaaR  
nFileLength = getFileSize(); VaQ}XM  
if(nFileLength == -1) *RuUf  
{ Nb B`6@r  
System.err.println("File Length is not known!"); Kx<bVK4"  
} 8(g:i#~  
else if(nFileLength == -2) F~* 5`o  
{ N:&^ql4  
System.err.println("File is not access!"); i(U*<1y  
} rRsLl/d  
else Dj<Vn%d*  
{ 7&T1RB'>  
for(int i=0;i<nStartPos.length;i++) D, 3x:nK  
{  Y9PG  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6'qs=Ql  
} z` gR*+  
for(int i=0;i<nEndPos.length-1;i++) B3I< $  
{ T_\GvSOI  
nEndPos = nStartPos[i+1]; T}4RlIZF  
} nnr(\r~  
nEndPos[nEndPos.length-1] = nFileLength; Qz/=+A/4  
} <Pf W  
} '<XG@L  
n*_FC  
ri\r%x  
//启动子线程 {},G xrQm  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Kq.)5%~>  
for(int i=0;i<nStartPos.length;i++) !FO||z(vb  
{ sq :ff  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y;Dw%m  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tSQ>P -O  
nStartPos,nEndPos,i); FQ O6w'  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 53l9s <bOQ  
fileSplitterFetch.start(); :r#FI".qx  
} a2p<HW;)m  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5ue{&z @T  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 81aY*\  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^Z}INUv]7  
nEndPos = " + nFileLength); iL5+Uf)E3  
// fileSplitterFetch[nPos.length-1].start(); seq S*^7  
nk6xavQji  
r[~K m5  
//等待子线程结束 NCl={O9<j  
//int count = 0; .Olq_wuH  
//是否结束while循环 >eJk)qM  
boolean breakWhile = false; >gVR5o  
srC'!I=s>8  
0! !pNK%(  
while(!bStop) JO1c9NyKr  
{ .\1XR  
write_nPos(); xT=|Uc0  
Utility.sleep(500); w3yI;P  
breakWhile = true; Vl'|l)b4W  
BBy/b c!  
B23R9.FK  
for(int i=0;i<nStartPos.length;i++) *a+~bX)18  
{ )7J@A%u  
if(!fileSplitterFetch.bDownOver) SD JAk&Z}R  
{ `Jz"rh-M  
breakWhile = false; 9~>;sjJk  
break; S W  
} ZRcY; ?  
} }vc C4 =t/  
if(breakWhile) / <y-pFTg  
break; cty.)e=  
nc&V59*   
FtE%<QHt  
//count++; +B*ygv:  
//if(count>4) WvN5IHo 8i  
// siteStop(); <PJwBA%{  
} mqtl0P0  
kS+*@o  
WFLT[j!1  
System.err.println("文件下载结束!"); [l'~>  
} PsLuyGR.<  
catch(Exception e){e.printStackTrace ();} 6C) G  
} +h[$\_y  
5H?`a7q N  
%.[GR  
//获得文件长度 KWhw@y-5j@  
public long getFileSize() eGnc6)x@C  
{ +mV4Ty  
int nFileLength = -1; ks'25tv}F  
try{ R+, tn,<<  
URL url = new URL(siteInfoBean.getSSiteURL()); v#D9yttO{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SAXjB;VH6  
httpConnection.setRequestProperty("User-Agent","NetFox"); f'R^MX2  
~@L$}Eu  
_X;5ORH"  
int responseCode=httpConnection.getResponseCode(); W^al`lg+y  
if(responseCode>=400) $Ne#F+M9x  
{ e 0!a &w  
processErrorCode(responseCode); k(hes3JV  
return -2; //-2 represent access is error N6yqA)z?;  
} {f)",#  
{P-KU RQ  
blxH`O!  
String sHeader; -Z]?v3 9  
sa*]q~ a  
/koNcpJ  
for(int i=1;;i++) 'du:Bxl`d4  
{ (q3(bH~T)  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I)DLnnQQ  
//Utility.log(in.readLine()); j3z&0sc2(0  
sHeader=httpConnection.getHeaderFieldKey(i); o_os;  
if(sHeader!=null) &|Z:8]'P  
{ vZ$uD,@;.  
if(sHeader.equals("Content-Length")) _0^<)OSY  
{ 8|V6RgA%  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [#uX{!q'  
break;  3]<$;[Q  
} 0(-'L\<>x  
} >iWl-hI-  
else Wc03Sv&FZ  
break; 0>Ecm#  
} <;SMczR  
} 3}n=od=  
catch(IOException e){e.printStackTrace ();} WynHcxC  
catch(Exception e){e.printStackTrace ();} H6rWb6i  
a*74FVZo.;  
0XL x@FYn  
Utility.log(nFileLength); PS(9?rX#+  
]@M$.msg@  
<E6]8SQE  
return nFileLength; b*r1Jn"h  
} :NS;y-{^^y  
MdZ7Yep  
nN/v7^^  
//保存下载信息(文件指针位置) GeZwbJ/?B  
private void write_nPos() A$fd6+{  
{ 6$ @Pk<w  
try{ )!p=0&z@{  
output = new DataOutputStream(new FileOutputStream(tmpFile)); <k/'mBDk  
output.writeInt(nStartPos.length); u|9^tHT>  
for(int i=0;i<nStartPos.length;i++) rWi9'6  
{ az0( 54M  
// output.writeLong(nPos); !tHqF  
output.writeLong(fileSplitterFetch.nStartPos); ObMsncn  
output.writeLong(fileSplitterFetch.nEndPos); 1wqCoDgkp  
} 8uS1HE\%  
output.close(); NzNAhlXj3  
} K'N\"Y?>  
catch(IOException e){e.printStackTrace ();} Yy>%dL  
catch(Exception e){e.printStackTrace ();} JL2IVENWc  
} duV|'ntr  
@+B .<@V  
C6CX{IA]  
//读取保存的下载信息(文件指针位置) GAtK1%nPD  
private void read_nPos() :#c?`>uV  
{ {HvR24#  
try{ Af ^6  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8+v6%,K2  
int nCount = input.readInt(); {Kd9}CDAZ  
nStartPos = new long[nCount]; Z(*n ZT,  
nEndPos = new long[nCount]; -:cS}I  
for(int i=0;i<nStartPos.length;i++) fC]+C(*d  
{ 6DR@$fpt  
nStartPos = input.readLong(); _(J- MCY\  
nEndPos = input.readLong(); hFj.d]S  
} j$&k;S  
input.close(); VH+^G)^)W  
} *Rr,ii  
catch(IOException e){e.printStackTrace ();} !0*=z~  
catch(Exception e){e.printStackTrace ();} =EsKFt"  
} ^*%p]r  
KW^s~j  
VlXIM,  
private void processErrorCode(int nErrorCode) m{(D*Vuqd  
{ ldanM>5  
System.err.println("Error Code : " + nErrorCode); DU]MMR  
} G\Toi98d*  
zZki9P   
u%VO'}Gz  
//停止文件下载 f![x7D$  
public void siteStop() \*!g0C 8 o  
{ "{qhk{  
bStop = true; 1Qhx$If~  
for(int i=0;i<nStartPos.length;i++) ;oWhTj`  
fileSplitterFetch.splitterStop(); Z UAWSJ,s  
sB-c'`,w`  
n*@^c$&P  
} /o+, =7hY  
} _BtppQIWv  
//负责部分文件的抓取 >:Xzv  
**FileSplitterFetch.java /$&~0pk  
*/ cJj0`@0f  
package NetFox; 7+#^:;19`  
</:f-J%U/  
!ny; YV  
import java.io.*; A}OV>yM  
import java.net.*; %w/o#*j<;  
>^D"%Oj y  
kh^AH6{2  
public class FileSplitterFetch extends Thread { qSkt }F%'  
p^5B_r:  
xm/v :hl=  
String sURL; //File URL }@SZ!-t%rD  
long nStartPos; //File Snippet Start Position .Z'CqBr[:  
long nEndPos; //File Snippet End Position 6"-LGK:  
int nThreadID; //Thread's ID -NiFO  
boolean bDownOver = false; //Downing is over A{y3yH`#h  
boolean bStop = false; //Stop identical (@uQ>dR:  
FileAccessI fileAccessI = null; //File Access interface g0cCw2S  
Qn[4&nUD  
P,CJy|[L  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException onG,N1`+  
{ (}gF{@sn  
this.sURL = sURL; +g7Iu! cA  
this.nStartPos = nStart; Q%o   
this.nEndPos = nEnd; o@EV>4e y  
nThreadID = id; @UkcvhH  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vb{&T<  
} i ,4  
J j yQ  
{ tim{nV  
public void run() j=PQoEtU'<  
{ q,QMvUK:  
while(nStartPos < nEndPos && !bStop) T/)$}#w0i  
{ #s(B,`?N  
<W|{zAyv  
9]1-J5iO  
try{ wb"Jj  
URL url = new URL(sURL); fG0rUi(8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @l$cZi e  
httpConnection.setRequestProperty("User-Agent","NetFox"); +_ K7x5g  
String sProperty = "bytes="+nStartPos+"-"; F{bET  
httpConnection.setRequestProperty("RANGE",sProperty); @>(l}5U5  
Utility.log(sProperty); 1S  0GjR  
y 9/27yWB  
$hg W>e  
InputStream input = httpConnection.getInputStream(); }1N)3~  
//logResponseHead(httpConnection); Ds&)0Iwf  
=QRLKo#_  
pFGdm3pV  
byte[] b = new byte[1024]; ;vQ7[Pv.j  
int nRead; Gv?3}8Wp  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) d3 fE[/oU  
{ wvx N6  
nStartPos += fileAccessI.write(b,0,nRead); |~8iNcIS  
//if(nThreadID == 1) ~Jp\'P7*  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rQj.W6w=  
} lv&<kYWY  
m#grtmyMrI  
,5t.0XqS  
Utility.log("Thread " + nThreadID + " is over!"); i\},  
bDownOver = true;  6.KR(V  
//nPos = fileAccessI.write (b,0,nRead); \hv*`ukF  
} YOP=gvZq  
catch(Exception e){e.printStackTrace ();} i. `S0  
} + 5sT GNG  
} 8l+\Qyj  
XZ Z Ml  
UMx>n18;f9  
//打印回应的头信息 'n)M0e  
public void logResponseHead(HttpURLConnection con) <3Co/.VQd  
{ Uu }ai."iB  
for(int i=1;;i++) ~WR6rc  
{ } Yj ic4?  
String header=con.getHeaderFieldKey(i); xJ^Gtq Um  
if(header!=null) SobK<6  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Fg5>CppH  
Utility.log(header+" : "+con.getHeaderField(header)); {B\ar+9>  
else )q&uvfQ1(  
break; )h2wwq0]  
} _9\ ayR>d  
} QOy+T6en  
DH)@8)C  
l'B`f)  
public void splitterStop() QmT]~4PqS  
{ NrNbNFfo  
bStop = true; %$!}MxUM  
} ?G0=\U< o,  
1UyI.U]  
/G G QO$'  
} Ur?a%]  
`Qaw]&O  
Y;xVB" (  
/* $N+a4  
**FileAccess.java Le|Ho^h,Y  
*//文件访问(定位,写) .QRQvtd.  
package NetFox; ran Q_\  
import java.io.*; (!W:-|[K\  
RfEmkb<9Z  
B~caHG1b  
public class FileAccessI implements Serializable{ >[O @u4  
sW3-JA]  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +\\,FO_  
RandomAccessFile oSavedFile; |v[{k>7f  
long nPos; % 89f<F\V  
;}=v|Dr&I.  
A4Q8^^byY  
public FileAccessI() throws IOException 1ncY"S/VO  
{ %]r@vjeyd  
this("",0); xo7H^!_   
} FTtYzKX(bv  
iW.8+?Xq&  
e@NS=U` <  
public FileAccessI(String sName,long nPos) throws IOException 6b6}HO  
{ Q$iv27  
oSavedFile = new RandomAccessFile(sName,"rw"); )O#>ONm^  
this.nPos = nPos; E`u=$~K  
oSavedFile.seek(nPos); a}hpcr({?  
} J+Q ;'J  
2/E3~X7  
5?kF'yksR  
public synchronized int write(byte[] b,int nStart,int nLen) F1w~f <  
{ jiC;*]n  
int n = -1; daGGgSbh  
try{ C8-4 m68"  
oSavedFile.write(b,nStart,nLen); kNd[M =%  
n = nLen; \m*?5]m ;  
} P7 H-Dw  
catch(IOException e) mI@E>VCV[  
{ st+X~;PX*  
e.printStackTrace (); ) $#ov-]  
} Gv?'R0s  
Ac^}wXp  
bo0m/hVU  
return n; j42U|CuK  
} ) e;)9~  
`.#e4 FBW  
6^if%62l&  
} V[HHP_  
8ooj)  
Qry?h*p+`  
/* }AdA? :7A  
**SiteInfoBean.java aN n\URR  
*/ Y*oT (  
package NetFox; w#ha ^4  
<*O~?=6p  
v8=7  
public class SiteInfoBean { u17e  
^B)iBf Z  
9em?2'ysa  
private String sSiteURL; //Site's URL =/_tQR~  
private String sFilePath; //Saved File's Path M A9Oi(L)K  
private String sFileName; //Saved File's Name ey4RKk,  
private int nSplitter; //Count of Splited Downloading File ue?e}hF  
%=C49(/K_  
>;|~ z\8  
public SiteInfoBean() oUXi 4lsSc  
{//nSplitter的缺省值为5 Hrz #So\#  
//default value of nSplitter is 5 GJ1ap^k  
this("","","",5); c -1Hxd YD  
} 5!GL"  
T4H/D^X|  
'x'.[=;  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Pr|:nJs  
{ _wvSLu<q  
sSiteURL= sURL; 0M[O(.x  
sFilePath = sPath; {[Bo"a>%  
sFileName = sName; h%2;B;p]  
this.nSplitter = nSpiltter; ,_ zivUU  
lt:xN?--A?  
3}U {~l!K  
} mPhrMcL  
R<"fcsU  
*RPdU.  
public String getSSiteURL() ?\_\pa/+  
{ 4$HU=]b6Tf  
return sSiteURL; Nd5G-eYI  
} f=$w,^)M  
2.xA' \M  
N*vBu `  
public void setSSiteURL(String value) M|HW$8V3_2  
{ :K-05$K  
sSiteURL = value; U^AywE]  
} BYh F?  
|$hBYw  
0[/GEY@  
public String getSFilePath() G&eRhif  
{ ?vnO@Bb/a  
return sFilePath; `a$c6^a  
} nTy8:k']  
@e`%'  
P@LFX[HtM  
public void setSFilePath(String value) S-^:p5{r  
{ *wvd[q h  
sFilePath = value; CtEpS<*c  
} ?%QWpKO7X  
[9hslk  
n5Coxvy1  
public String getSFileName() R]LRgfi9  
{ ?2RDd|#  
return sFileName; xOKLc!J  
} V8C62X  
C i?BJ,  
FrKI=8  
public void setSFileName(String value) ~g#$'dS  
{ E4C yW  
sFileName = value; QsO%m  
} B4l*]K%  
hggP9I :s,  
nfj8z@!  
public int getNSplitter() z_;:6*l=:  
{ 80'!XKSP  
return nSplitter; > TKl`O  
} ?3duW$`  
?W27 h  
Xur{nk~?  
public void setNSplitter(int nCount) O4+a[82  
{ c[E "  
nSplitter = nCount; k <EzYh  
} b +4x2{  
} /QgU!:e  
*v}3So  
oe4r_EkYwW  
/* QEC4!$L^  
**Utility.java S;I>W&U  
*/ -ff@W m  
package NetFox; ><HHO (74X  
)j_Y9`R  
[& d"Z2gK  
public class Utility { u/ Gk>F  
\>G:mMk/  
0#/NZO  
public Utility() U!TSAg21P  
{ crDm2oA~t  
J#/L}h;qH  
##\ <mFE  
} *LZB.84  
FD1Z}v!5IJ  
//线程睡眠 =O.%)|  
public static void sleep(int nSecond) H\PY\O&cP  
{ m4m,-}KNi  
try{ J ,s9,("  
Thread.sleep(nSecond); iVUkM3  
} &{R]v/{p]  
catch(Exception e) SK]"JSY`  
{ f|r +qe  
e.printStackTrace (); ,q".d =6  
}  {F'~1qf  
} 5ns.||%k  
jE#&u DfI  
//日志 Y CBcyE}p  
public static void log(String sMsg) bT8 ?(Iu  
{ \'>8 (i~  
System.err.println(sMsg); Rf4}4ixkj  
} j@guB:0  
d1{%z\u a  
ExW3LM9(  
public static void log(int sMsg) Vz\?a8qQ<  
{ +\ZaVi  
System.err.println(sMsg); P.t0o~hoK;  
} e.n*IJ_fz  
} hgU#2`fS  
!xRboPg  
U#mrbW  
/* &2Q0ii#Aa  
**TestMethod.java Y@#rGV>  
*/ >39\u &)  
package NetFox; V|q`KOF  
v-MrurQ4  
uJ:SN;  
public class TestMethod { },& =r= B  
B s{n  
Be4n\c.  
public TestMethod() p+y2w{{  
{ ///xx/weblogic60b2_win.exe D&]dlY@*  
try{ D:I6nSoC  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); YsBOh{Ml  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "3H?_!A9  
SiteFileFetch fileFetch = new SiteFileFetch(bean); wc~k4B9"  
fileFetch.start(); ][[\!og  
} 9bb 5?b/  
catch(Exception e){e.printStackTrace ();} L>X39R~  
vUD>+*D  
6?uo6 I  
} lD]/Kx  
){M)0,:  
bmd3fJb`r  
public static void main(String[] args) |Ev V S  
{ J69B1Yi  
new TestMethod(); yu9 8d1  
} .8~zgpK  
} [ }1+=Ub  
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