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http断点续传简单实现(java)

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/* ! JA;0[;l=  
**SiteFileFetch.java 8e?/LA%MU  
*/ =Pv_,%  
package NetFox; *I 1H  
import java.io.*; X%b1KG|#(  
import java.net.*; %mC@}  
ny{C,1QG  
Om*QN]lGq  
public class SiteFileFetch extends Thread { CY o m  
ILm +o$o ~  
(H_dZL  
SiteInfoBean siteInfoBean = null; //文件信息Bean '?C6P5fm  
long[] nStartPos; //开始位置 7Bj,{9^aJ  
long[] nEndPos; //结束位置 M hN;GMH  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 -,")GA+[7  
long nFileLength; //文件长度 ! VR&HEru  
boolean bFirst = true; //是否第一次取文件 D1rVgM  
boolean bStop = false; //停止标志 u=0O3-\h  
File tmpFile; //文件下载的临时信息 {JfQQP&FV  
DataOutputStream output; //输出到文件的输出流 |<Ls;:5.  
\\SQACN  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 1gHe$ dzXk  
public SiteFileFetch(SiteInfoBean bean) throws IOException yV.p=8:  
{ ]c>@RXY'  
siteInfoBean = bean; m[}P  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); v_XN).f;  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); kk78*s {6  
if(tmpFile.exists ()) v +4v  
{ 2W+~{3[#  
bFirst = false; vzS b(  
read_nPos(); C&z!="hMhR  
} "L2*RX.R  
else jZ.yt+9  
{ T ipH}  
nStartPos = new long[bean.getNSplitter()]; ?("O.<  
nEndPos = new long[bean.getNSplitter()]; ^BF}wQb :j  
} &ZD@-"@  
8xB-cE  
wlNL;W@w  
dWn6-es  
} B''yW{  
^ 9+ Qxv  
v*.R<- X:  
public void run() )=f}vHg$  
{ O?OAXPK2  
//获得文件长度 jq H)o2"/  
//分割文件 hJM& rM7  
//实例FileSplitterFetch eDpi0htm  
//启动FileSplitterFetch线程 htB7 j(  
//等待子线程返回 +;W%v7 %<  
try{ Gj?Zbl <  
if(bFirst) =n,;S W  
{ R%.`h  
nFileLength = getFileSize(); U =J5lo  
if(nFileLength == -1) {L;sF=d  
{ ;VLDXvGd  
System.err.println("File Length is not known!"); ^/#+0/Bn  
} G`l\R:Q  
else if(nFileLength == -2) Lip#uuuXXN  
{ %gmx47  
System.err.println("File is not access!"); Bj 7* 2}  
} 1>e30Ri,g  
else 0~U0s3  
{ o(ow{S@=4  
for(int i=0;i<nStartPos.length;i++) s* GZOz  
{ i~Tt\UA>  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); xCZ_x$bk  
} P|Aac,nE+^  
for(int i=0;i<nEndPos.length-1;i++) _&, A  
{ |!(8c>]Bo  
nEndPos = nStartPos[i+1]; l`\L@~ln  
} d.f0OhQ  
nEndPos[nEndPos.length-1] = nFileLength; =b%f@x_U1  
} Z8=?Hu  
} b%lB&}uw}  
HwFg;r  
TFkG"ev  
//启动子线程 PzPNvV/o  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 437Wy+Q|e  
for(int i=0;i<nStartPos.length;i++) +nR("Il  
{ eP2Q2C8g  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dSwfea_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _YX% M|#  
nStartPos,nEndPos,i); 04U|Frc  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }tt%J[  
fileSplitterFetch.start(); 1 fcV&qHR  
} l-w4E"n3  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3}}/,pGSc  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); eY 3:Nl^  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]L~z9)  
nEndPos = " + nFileLength); }4>u_)nt  
// fileSplitterFetch[nPos.length-1].start(); ^x&x|ckR!  
wwl,F=| Y  
u [qy1M0  
//等待子线程结束 U,2OofLM  
//int count = 0; St?mq* ,  
//是否结束while循环 D:9^^uVp  
boolean breakWhile = false; #<Y.+ :  
Q%O9DCi  
SL uQv?R}9  
while(!bStop) KJFQ)#SW!  
{ p>)1Z<D"a  
write_nPos(); =+X*$'<J  
Utility.sleep(500); ;,-)Z|W  
breakWhile = true; |Kd6.Mx  
@ fMlbJq  
vE9"1M  
for(int i=0;i<nStartPos.length;i++) dFg&|Lp  
{ {b-C,J  
if(!fileSplitterFetch.bDownOver) 6Y[&1c8  
{ s>;"bzzq  
breakWhile = false; DSs/D1mj&  
break; <vl(a*4a  
} )[hs#nKTh  
} ^(&2  
if(breakWhile) ^RnQX#+  
break; Y<;C>Rs  
>> cW0I/`  
Q+f |.0r  
//count++; !}c D e12  
//if(count>4) HV!P]82Pa  
// siteStop(); Jha*BaD~N  
} U+VJiz<!  
<@`K^g;W  
{Q/@Y.~<  
System.err.println("文件下载结束!"); d '2JMdbc  
} gS(JgN  
catch(Exception e){e.printStackTrace ();} _$*-?*V&  
} 'tTlBf7#  
Db2#QQ  
+PYR  
//获得文件长度 p3fV w]N  
public long getFileSize() >]}VD "\  
{ RCqL~7C+ k  
int nFileLength = -1; 3Dc^lfn  
try{  ~@@t-QY  
URL url = new URL(siteInfoBean.getSSiteURL()); F@/syX;bb5  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TJ>YJ D  
httpConnection.setRequestProperty("User-Agent","NetFox"); kk126?V]_  
w32F?78]  
W9cvxsox  
int responseCode=httpConnection.getResponseCode(); Nj6Np^@sH  
if(responseCode>=400) p,WBF  
{ Rt%Dps%  
processErrorCode(responseCode); f~d =1  
return -2; //-2 represent access is error _BG `!3U+  
} Ge$&k  
Q3lVx5G>4  
>ptI!\i}  
String sHeader; Q m9b:U~  
 UDpI @  
$_ $%L0)5  
for(int i=1;;i++) #euOq  
{ j5Yli6r?3-  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q&ed4{H<  
//Utility.log(in.readLine()); EHe-wC  
sHeader=httpConnection.getHeaderFieldKey(i); f].z.  
if(sHeader!=null) PmId #2f  
{ a[^dK-  
if(sHeader.equals("Content-Length")) F`Vp   
{ 0wBr_b!  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;Xidv9c  
break; d{!zJ+n  
} J!rZs kd  
} -'W:P'BG  
else P)TeF1~T  
break; ?fs#K;w  
} ^<yM0'0t  
} XSZjuQ<[3  
catch(IOException e){e.printStackTrace ();} :\#]uDT2=  
catch(Exception e){e.printStackTrace ();} VyU!r* o  
r'}#usB(  
\@2sI  
Utility.log(nFileLength); ,38bT#p:,r  
/9y'UKl7[  
!x:w2  
return nFileLength; RAyR&p  
} Y!E| X 3  
1?+)T%"  
x^F2Ywp%  
//保存下载信息(文件指针位置) '.&,.E&{$  
private void write_nPos() y(#F&^|  
{ hYCyc -W  
try{ GLl@ 6S>v  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZG)C#I1;O  
output.writeInt(nStartPos.length); -JF|770i  
for(int i=0;i<nStartPos.length;i++) \No22Je6d  
{ a7NX~9 g  
// output.writeLong(nPos); K3UG6S\B  
output.writeLong(fileSplitterFetch.nStartPos); Q!%CU8!`&  
output.writeLong(fileSplitterFetch.nEndPos); I(WND/&  
} $PbN=@  
output.close(); Y@'1}=`J  
} #iGz&S3iN$  
catch(IOException e){e.printStackTrace ();} P3XP=G`E  
catch(Exception e){e.printStackTrace ();} (Gxv?\  
} D+_PyK~ jc  
X'bp?m  
}Lwj~{  
//读取保存的下载信息(文件指针位置) **YNR:#Y  
private void read_nPos() 48%a${Nvvj  
{ Ah2XwFg?  
try{ @p2dXJeR<  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =09j1:''<d  
int nCount = input.readInt(); *DoEDw  
nStartPos = new long[nCount]; ~h[lu^ZSi  
nEndPos = new long[nCount]; {_MU0=7c\  
for(int i=0;i<nStartPos.length;i++) '*p-`  
{ J>Rt2K  
nStartPos = input.readLong(); =Jl1D*B*  
nEndPos = input.readLong(); Pq7tNM E  
} TAJ9Y<  
input.close(); Y=rW.yK8  
} Js#c9l{{  
catch(IOException e){e.printStackTrace ();} `TsfscN  
catch(Exception e){e.printStackTrace ();} vDOeBw=  
} IO_H%/v"jC  
7erao-  
<ct{D|mm  
private void processErrorCode(int nErrorCode) #WpO9[b>  
{ Z*e7W O.  
System.err.println("Error Code : " + nErrorCode); t@19a6:Co  
} nt[0krG  
" Gn; Q-@  
yZ)ScB^  
//停止文件下载 s*#|EdD6@  
public void siteStop() #XY]@V\  
{ cwC, VYVl  
bStop = true; J2[QHr&tn  
for(int i=0;i<nStartPos.length;i++) qP<,"9!I  
fileSplitterFetch.splitterStop(); \T]"pE+8l  
UZX)1?U  
>qUO_>  
} 8"* $e I5  
} >%3c1  
//负责部分文件的抓取 :3n.nKANr  
**FileSplitterFetch.java ng<`2XgU  
*/ tw3d>H`  
package NetFox; 'IW+"o  
kWz%v  
rqh,BkQ0t  
import java.io.*; QBn>@jq  
import java.net.*; &{=~)>h  
Tk2kis(n  
m[7:p{  
public class FileSplitterFetch extends Thread { h'fD3Gr&  
Sf'5/9<DW+  
w+$gY?%  
String sURL; //File URL q(p0#Mk,E  
long nStartPos; //File Snippet Start Position eB@i)w?@o  
long nEndPos; //File Snippet End Position =K>Z{% i  
int nThreadID; //Thread's ID I2DmM"-|  
boolean bDownOver = false; //Downing is over aQmL=9  
boolean bStop = false; //Stop identical d=KOV;~);  
FileAccessI fileAccessI = null; //File Access interface \j;uN#)28  
cnPX vD^kY  
(MIw$)#^  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException xR&,QrjQG  
{ dS&8R1\>1  
this.sURL = sURL; jRkq^}  
this.nStartPos = nStart; K]Cvk%  
this.nEndPos = nEnd; ;Gs**BB&  
nThreadID = id; C;) xjZiR  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _~(Xd@c(  
} :{ T#M$T  
3ElpS^ 2W  
l=]vC +mU  
public void run() n1/lE)  
{ Wkk Nyg,  
while(nStartPos < nEndPos && !bStop) 1;gSf.naG  
{ 2!otVz! Mh  
">QY'r  
bgK(l d`  
try{ QPcB_wUqu  
URL url = new URL(sURL); >oNk(. %  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z%{f[|h9}  
httpConnection.setRequestProperty("User-Agent","NetFox"); '> Q$5R1  
String sProperty = "bytes="+nStartPos+"-"; U ^9oc&  
httpConnection.setRequestProperty("RANGE",sProperty); S+y2eP G  
Utility.log(sProperty); =5M>\vt]  
F`Y<(]+   
KUyJ"q<W  
InputStream input = httpConnection.getInputStream(); YcV~S#b  
//logResponseHead(httpConnection); h^*{chm]  
<"+C<[n.  
RM+E  
byte[] b = new byte[1024]; KRZV9AJ  
int nRead; oCYD@S>h  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /nP=E  
{ 6;pREM+  
nStartPos += fileAccessI.write(b,0,nRead); v+sbRuo8  
//if(nThreadID == 1) r*wKYb  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F]*-i 55S  
} 7&)F;;H  
k9xKaJ %1  
cj<@~[uw  
Utility.log("Thread " + nThreadID + " is over!"); gAY2|/,  
bDownOver = true; `@D4?8_  
//nPos = fileAccessI.write (b,0,nRead); !gf3%!%  
} UVJ(iNK"  
catch(Exception e){e.printStackTrace ();} VC(|t} L4  
} [alXD_  
} 0cUt"(]  
~m?~eJK#a  
K-u/q6ufK  
//打印回应的头信息 j2Y(Q/i  
public void logResponseHead(HttpURLConnection con) ;#i$0~lRl  
{ o {LFXNcg[  
for(int i=1;;i++) ,GnU]f  
{ z0[ZO1Fo(  
String header=con.getHeaderFieldKey(i); >2 qP  
if(header!=null) RWo B7{G  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B-|Zo_7  
Utility.log(header+" : "+con.getHeaderField(header)); UYOn p7R<  
else \W^+vuD8  
break; N=wy)+  
} y}HC\A77uD  
} KgWT&^t  
p ri{vveN@  
=3C)sz}  
public void splitterStop()  Zwns|23n  
{ r![JPhei  
bStop = true; n^02@Aw  
} - (}1o9e\7  
tlgvBRH>  
"'B%.a#k  
} Sg>0P*K@  
!y~b;>887  
j]"xck  
/* !@Lc/'w  
**FileAccess.java CHit  
*//文件访问(定位,写) E57{*C  
package NetFox; 1<`7MN  
import java.io.*; p\;)^O4  
~J{[]wi  
E}9ldM=]s  
public class FileAccessI implements Serializable{ C}'="g^=sl  
?(8%SPRk  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y?#J`o- O  
RandomAccessFile oSavedFile; B!ibE<7,  
long nPos; g+)\ /n|  
yKEFne8^  
,D2_Z]  
public FileAccessI() throws IOException gCr|e}w-  
{ L_K\i?  
this("",0); _C,@eu"9V  
} f\U&M,L\ '  
UH-uU~  
{FY[|:Cp  
public FileAccessI(String sName,long nPos) throws IOException zf>^2t*\  
{ xevP2pYG:  
oSavedFile = new RandomAccessFile(sName,"rw"); n(YHk\2  
this.nPos = nPos; /8t+d.r;/  
oSavedFile.seek(nPos); l )*,18n  
} cievC,3*  
CN~NyJL H  
PFy;qk  
public synchronized int write(byte[] b,int nStart,int nLen) 65#:2,s  
{ ?VP!1O=J  
int n = -1; / &D$kxz  
try{ \R\@t] >Y  
oSavedFile.write(b,nStart,nLen); L2.`1Aag  
n = nLen; k5;Vl0Ho  
} KI@    
catch(IOException e) xf"5<PTW</  
{ E+ 3yN\X(  
e.printStackTrace (); auTTvJ  
} ]Bd3d%  
)QCM2  
&_/%2qs  
return n; "=\_++  
} 6eYf2sZ;J  
=l2Dm  
uV}WSoq[  
} 0O,T=z[+>  
oA;Ty7s  
^h6$> n5  
/*  Vm;Q w  
**SiteInfoBean.java 6$fnQcpJ  
*/ ~J>gVg%66  
package NetFox; =Cy>$/H64  
sC5uA .?>9  
4!~ .6cp3  
public class SiteInfoBean { Qj<{oZp&  
YG 5Z8@kH  
0SY f<$  
private String sSiteURL; //Site's URL _p J_V>l  
private String sFilePath; //Saved File's Path ca/o#9:N`:  
private String sFileName; //Saved File's Name yaRcBT?  
private int nSplitter; //Count of Splited Downloading File !\#Wk0Ku  
%:w% o$  
"4ozlWx  
public SiteInfoBean() s w.AfRQP  
{//nSplitter的缺省值为5 FL#g9U>  
//default value of nSplitter is 5 S`@6c$y k  
this("","","",5); ^/C $L8#  
} {#1j"  
2'<=H76  
De nt?  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Awa|rIM  
{ |v$%V#Bo  
sSiteURL= sURL; \YlF>{LVe  
sFilePath = sPath; -M:hlwha  
sFileName = sName; C?60`^  
this.nSplitter = nSpiltter; +eBMn(7Cgv  
A!ioji+{[  
{;iH Yr-zs  
} /}nrF4S  
_D>as\dP  
88#qu.  
public String getSSiteURL() hk@`N;dn  
{ B]|6`UfB  
return sSiteURL; vNz;#Je  
} \U!@OX.R'M  
OJ35En  
d2A wvP  
public void setSSiteURL(String value) I>H;o{X#  
{ %|*nmIPq(  
sSiteURL = value; Foe>}6~{?  
} 9'n))%CZ.  
xi?P(s A  
^$=tcoQG  
public String getSFilePath() e|b~[|;*=  
{ `&u<aLA  
return sFilePath; [Y22Wi  
} fwi};)K  
1C0Y0{6,  
Hz]4AS  
public void setSFilePath(String value) DIG0:)4R.  
{ 5@ bc(H  
sFilePath = value; c{mKra  
} >P\h,1  
A,m4WO_q3  
DHm[8 Qp  
public String getSFileName() ~JwpNJs  
{ ShWHHU(QQ  
return sFileName; G{NSAaD[  
} CJ9cCtA  
%XJQ0CE<(  
w.J%qWJq  
public void setSFileName(String value) GSz @rDGY  
{ k-WHHoU>o  
sFileName = value; Qj 6gg  
} cc|CC Zl  
*.m{jgi1X  
Yzj%{fkh  
public int getNSplitter() IjG5X[@  
{ /~i.\^HX  
return nSplitter; Gr5`1`8|  
} ~@T+mHny  
X0y?<G1( a  
i>Z|6 5  
public void setNSplitter(int nCount) Lw>-7)  
{ F8{ldzh  
nSplitter = nCount; M`0(!Q}  
} ]u rK$   
} 2#z=z d  
Qm.z@DwFM{  
;W7hc!  
/* mi7sBA9L8  
**Utility.java l^k+E-w\  
*/ Mjb 1  
package NetFox; |x &Z~y  
V~OUE]]Q  
O.*jR`l  
public class Utility { { EA2   
`nT?6gy  
2B HKS-J*  
public Utility() W1xf2=z`)T  
{ 2Sge  
pO"m~mpA  
1^aykrnQ>  
} ;"1/#CY773  
&&X$d!V  
//线程睡眠  bt;lq!g  
public static void sleep(int nSecond) fd4;mc1T  
{ @&?a]>L  
try{ W|;nJs:e  
Thread.sleep(nSecond); P?^JPbfV  
} 3PfiQ|/b  
catch(Exception e) <z^SZ~G  
{ }%eDEM  
e.printStackTrace (); 5pO]vBT  
} hzaU8kb  
} cX2$kIs;  
__ 8&Jv\  
//日志 KzV.+f  
public static void log(String sMsg) FyCBN tCv  
{ e\`wlaP,  
System.err.println(sMsg); z~F37]W3[  
} {3_Gjb5\\4  
}A-{6Qe  
f[x~)=  
public static void log(int sMsg) V {p*z  
{ x@h tx?   
System.err.println(sMsg); J;S-+  
} (FuEd11R  
} {`a(Tl8V  
8Bq-0=E  
8+9\7*  
/* Tj=gRQ2v  
**TestMethod.java UL&} s_  
*/ -(!uC +BZX  
package NetFox; K k7GZ  
U<Vy>gIC  
=tq1ogE  
public class TestMethod { 6VC-KY  
4iwf\#  
v{r1E]rY  
public TestMethod() iecWa:('  
{ ///xx/weblogic60b2_win.exe /^Y[*5  
try{ GjEqU;XBi  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kL|\wci  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rR\;G2p)  
SiteFileFetch fileFetch = new SiteFileFetch(bean); EOhC6>ATh  
fileFetch.start(); q]K'p,'  
} 975 _d_U  
catch(Exception e){e.printStackTrace ();} xpAok]  
^CUSlnB\(  
I`NUurQTX  
} n,CD  
!:3^ hb  
M_Bu,<q^  
public static void main(String[] args) *#zS^b n  
{ m~;B:LN<  
new TestMethod(); !~)90Z!  
} u\f3qc,]F  
} ?IILt=)<  
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