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http断点续传简单实现(java)

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/* 1~ Nz6  
**SiteFileFetch.java ^iNR(cwgX  
*/ mLE`IKgd]  
package NetFox; ] ?(=rm9u  
import java.io.*; 7|rT*-Ia  
import java.net.*; 1o%Hn"uG  
 t2iFd?  
rtm28|0H'  
public class SiteFileFetch extends Thread { 4hIC&W~f  
t At+5H  
kWFR(J&R  
SiteInfoBean siteInfoBean = null; //文件信息Bean )Pq.kn{Sp  
long[] nStartPos; //开始位置 K4BMa]/U  
long[] nEndPos; //结束位置 X*KT=q^?n  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 |4vk@0L  
long nFileLength; //文件长度 P; Ox|  
boolean bFirst = true; //是否第一次取文件 ]7;;uhn`  
boolean bStop = false; //停止标志 ']Z8C)tK  
File tmpFile; //文件下载的临时信息 G1rgp>m  
DataOutputStream output; //输出到文件的输出流 dkjL;1  
B_> Fd&  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }R^{<{KVJ  
public SiteFileFetch(SiteInfoBean bean) throws IOException {`VQL6(i  
{ h.nzkp5  
siteInfoBean = bean; /NZ R|  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); I8y\D,  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); \GWC5R7Q0j  
if(tmpFile.exists ()) a'BBp6  
{ 1Q<a+ l  
bFirst = false; Yh=Zn[ U  
read_nPos(); eo!z>9#.  
}  BeQJ/`  
else zx27aZ[  
{ 3?:}lY<,  
nStartPos = new long[bean.getNSplitter()]; Eq t61O$x  
nEndPos = new long[bean.getNSplitter()]; <$E8T>U  
} M5]w U   
#/T)9=m  
/-T%yuU  
lI9 3{!+>  
} y03l_E,  
HM/ q B^  
7DD ot_qb  
public void run() kDsUKO p  
{ rAWBuEU;!  
//获得文件长度 i> ;G4  
//分割文件 [{YV<kN  
//实例FileSplitterFetch %llG/]q#  
//启动FileSplitterFetch线程 l<5!R;?$  
//等待子线程返回 j2+&B9 (  
try{ N}\i!YUD  
if(bFirst) =$MV3]  
{ /9sUp} *  
nFileLength = getFileSize(); m35G;  
if(nFileLength == -1) )j](_kvK  
{ V%))%?3x_  
System.err.println("File Length is not known!"); @ B+];lr/-  
} I8m(p+Z=  
else if(nFileLength == -2) /Mv'fich(  
{ D3eK!'qS  
System.err.println("File is not access!"); Js'|N%pi  
} >Q YxX<W  
else @I%m}>4Jm  
{ : M Md@  
for(int i=0;i<nStartPos.length;i++) 4R6X"T9-  
{ {+!_; zzZ  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 2l9_$evK~  
} kns[b [!H  
for(int i=0;i<nEndPos.length-1;i++) s:%>H|-  
{ NFQ0/iuW  
nEndPos = nStartPos[i+1]; `| fF)kI  
} FkH4|}1  
nEndPos[nEndPos.length-1] = nFileLength; xaPTTa  
} aD.A +es  
} D`u{U]  
Q,>AT$|  
mWZV O,t$  
//启动子线程 ;I9D>shkc  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H=0Y4 T@)T  
for(int i=0;i<nStartPos.length;i++) [.2>=3T  
{ fSj^/>  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f.!cR3XgV  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~`y6YIJ3  
nStartPos,nEndPos,i); B|!Re4`0  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0'gJSrgNI  
fileSplitterFetch.start(); )pg?ZM9  
} ;(z0r_p<q  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uJi|@{V  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fNQecDuS  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {L#Pdj{  
nEndPos = " + nFileLength); h>4\I;Ij  
// fileSplitterFetch[nPos.length-1].start(); XWkYhTaY  
!O*\|7A(  
<|v]9`'  
//等待子线程结束 VP[ J#TPU  
//int count = 0; zzM 'uo  
//是否结束while循环 C@xh$(y  
boolean breakWhile = false; 86[T BX5'  
TtHqdKL  
o_?YYw-:  
while(!bStop) 1g *4e  
{ J 9z\ qTI  
write_nPos(); 0 ~VniF^  
Utility.sleep(500); zH.7!jeE  
breakWhile = true; 0 j6/H?OT  
"/K44(^  
zT.qNtU%  
for(int i=0;i<nStartPos.length;i++) nM@S`"  
{ w9vqFtj  
if(!fileSplitterFetch.bDownOver) `Dj-(~x  
{ $cc]pJy"}  
breakWhile = false; QHK$2xtq|  
break; )8yNqnD  
} B&cC;Hw  
} .QW89e,O3  
if(breakWhile) jfk`%C Ek=  
break; cO' \s  
fxjs"rD5  
}.x?$C+\"  
//count++;  a(F%M  
//if(count>4) ='a$>JVJ5  
// siteStop(); XSXS;Fh)  
} Nb-;D)W;B  
1I_(!F{Ho  
~h -0rE  
System.err.println("文件下载结束!"); c'[l%4U8[  
} 5MT$n4zKu  
catch(Exception e){e.printStackTrace ();} -r[l{ce  
} l9\ *G;  
"+p_{J/P  
2-FL&DE  
//获得文件长度 ;:f.a(~c  
public long getFileSize() t=5 K#SX}  
{ 7&E3d P  
int nFileLength = -1; Ao(Xz$cQfW  
try{ YHl6M&*@  
URL url = new URL(siteInfoBean.getSSiteURL()); IF<pT)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); awGI|d  
httpConnection.setRequestProperty("User-Agent","NetFox"); (z\@T`6`  
tQF,E&Jo8  
}PD? x4  
int responseCode=httpConnection.getResponseCode(); 8ex{N3  
if(responseCode>=400) .cjSgK1  
{  LGV"WE  
processErrorCode(responseCode); $o0o5 ^Z-  
return -2; //-2 represent access is error n)gzHch  
} ) m[0,  
$)mK]57  
]:d`=V\&N  
String sHeader; }[k~JXt  
V0XQG}  
h#a,<B|  
for(int i=1;;i++) b|P[\9  
{ hvkLcpE  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @h$cHZ  
//Utility.log(in.readLine());  [td)v,  
sHeader=httpConnection.getHeaderFieldKey(i); -)PQ&[  
if(sHeader!=null) <`}Oi 5nW  
{ 1Jjay#  
if(sHeader.equals("Content-Length")) E)7vuWO O  
{ f%;8]a9  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); unKi)v1  
break; u,I_p[`E  
} 0"#'Z>"  
} NJRk##Z  
else _SY4Q s`d  
break; 1:(qoA:  
} R.-2shOE'  
} @lRTp  
catch(IOException e){e.printStackTrace ();} fYBmW')  
catch(Exception e){e.printStackTrace ();} KEEHb2q  
>+ul LQqe  
f%<kcM2  
Utility.log(nFileLength); Cz` !j  
&'Pwz  
2r4owB?  
return nFileLength; J'jwRn  
} BIqZg$  
ux:czZqy  
@z[,w`  
//保存下载信息(文件指针位置) mII7p LbQ  
private void write_nPos() ..'k+0u^  
{ cks53/Z  
try{ ~PAF2  
output = new DataOutputStream(new FileOutputStream(tmpFile)); $dIu${lu  
output.writeInt(nStartPos.length); 'B>fRN  
for(int i=0;i<nStartPos.length;i++) AwN7/M~'  
{ LlKvi_z  
// output.writeLong(nPos); ji9 (!G  
output.writeLong(fileSplitterFetch.nStartPos); "^Y)&<J&  
output.writeLong(fileSplitterFetch.nEndPos); {}RE;5n\['  
} }86&? 0j.  
output.close(); GG<{n$h  
} ^E{M[;sF3y  
catch(IOException e){e.printStackTrace ();} bk^W]<:z`  
catch(Exception e){e.printStackTrace ();} LX;w~fRr.  
} QhR.8iS  
Z\c^CN  
IYAvO%~  
//读取保存的下载信息(文件指针位置) 4LO4SYW7  
private void read_nPos() YW9r'{(D(I  
{ )lh48Ag0t;  
try{ iYJ:P  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <?yf<G'$  
int nCount = input.readInt(); dp;;20z  
nStartPos = new long[nCount]; F<H[-k*t/  
nEndPos = new long[nCount]; Av6=q=D  
for(int i=0;i<nStartPos.length;i++) HmlE Cx  
{ =A[:]),v  
nStartPos = input.readLong(); VAPRI\uM;  
nEndPos = input.readLong(); `TwDR6&  
} YD>5zV%!D  
input.close(); 3h N?l :/b  
} b/;!yOF  
catch(IOException e){e.printStackTrace ();} :buH\LB*P  
catch(Exception e){e.printStackTrace ();} 17kh6(X  
}  KT'Ebb]  
K=lm9K  
PY.4J4nn|  
private void processErrorCode(int nErrorCode) IY_u|7d  
{ ^K[WFiN}  
System.err.println("Error Code : " + nErrorCode); k+qxx5{  
} F9h'.{@d  
}#'I,?_k  
^jY/w>UdH  
//停止文件下载 FVY$A =G  
public void siteStop() 6WI-ZEVp&  
{ pAK7V;sJ  
bStop = true; gbf2ty  
for(int i=0;i<nStartPos.length;i++) <7  
fileSplitterFetch.splitterStop(); j<,Ho4v}_  
B"; >zF  
<;eXbO>Q  
} "&9L  
} F"I{_yleq'  
//负责部分文件的抓取 7 k:w3M  
**FileSplitterFetch.java \Dn47V{7-  
*/ M8Tj;ATr  
package NetFox; (g(.gN]  
l  rRRRR  
XHN*'@ 77;  
import java.io.*; I| V yv  
import java.net.*; '>"riEk  
cpY'::5.%  
8VWkUsOoI  
public class FileSplitterFetch extends Thread { gC/~@Z8W]  
<t~RGn3  
n7EG%q6m+  
String sURL; //File URL NI<;Lm  
long nStartPos; //File Snippet Start Position 5>S=f{ghFw  
long nEndPos; //File Snippet End Position @Yzdq\FI  
int nThreadID; //Thread's ID :NCY6? [Dz  
boolean bDownOver = false; //Downing is over r:.ydr@  
boolean bStop = false; //Stop identical k_,wa]ws$  
FileAccessI fileAccessI = null; //File Access interface T> < Vw  
&7 0o4~Fr  
dGc<{sQzB  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n "J+? ~9  
{ %@q/OVnM  
this.sURL = sURL; ^i;y2c  
this.nStartPos = nStart; O>vbAIu  
this.nEndPos = nEnd; {p90   
nThreadID = id; $E >)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =cP7"\  
} HxE`"/~.7k  
)8,)&F  
p?Rq  
public void run() dv7IHUFf  
{ fR^aFT  
while(nStartPos < nEndPos && !bStop) q8=hUD%5C  
{ ' K\ $B_  
Fv!KLw@  
@lO(QpdG  
try{ _T^+BUw  
URL url = new URL(sURL); VV%Q "0 \  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yG/_k !{9  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;,&$ob*/  
String sProperty = "bytes="+nStartPos+"-"; /4xp?Lo:  
httpConnection.setRequestProperty("RANGE",sProperty); KD(}-zUs  
Utility.log(sProperty); S-Z s  
0*4h}t9j  
_Pe,84Ro  
InputStream input = httpConnection.getInputStream(); ]+)cXJ}6#  
//logResponseHead(httpConnection); G&DL)ePu]m  
No(p:Snbo  
PKK18E}{%^  
byte[] b = new byte[1024]; ^6?)EM#  
int nRead; nyRQ/.3  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wU $j/~L  
{ kCVO!@yZz  
nStartPos += fileAccessI.write(b,0,nRead); N5%Cwl6i  
//if(nThreadID == 1) <q<kqy5s-R  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,bU 8S\8  
} h+"UK=  
c&]nAn(  
&}."sGK  
Utility.log("Thread " + nThreadID + " is over!"); EZw<)Q   
bDownOver = true; 7wA.:$  
//nPos = fileAccessI.write (b,0,nRead); e^ ZxU/e  
} %]iE(!>3oy  
catch(Exception e){e.printStackTrace ();} ,JVWn>s  
} AzlZe\V?)~  
} g UAx8=h  
%.nZ@';.  
P)9$}9i  
//打印回应的头信息 mu/GOEZ5  
public void logResponseHead(HttpURLConnection con) ?V9Da;cj  
{ *? <ygzX  
for(int i=1;;i++) (7k}ysc  
{ Q"VS;uh.v  
String header=con.getHeaderFieldKey(i); ))xyaYIZkk  
if(header!=null) 6|HxBC#4  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #l<un<  
Utility.log(header+" : "+con.getHeaderField(header)); m R|;}u;d  
else +/|;<K5_LI  
break; %fH&UFby  
} 9%  wVE]  
} NKX62 ZC  
*l9Wj$vja  
'ai3f  
public void splitterStop() wx]r{  
{ [.[|rnil  
bStop = true; X 8#Uk}/  
} f?P>P23  
\]7i-[  
3Gyw^_{J  
} Kb icP<  
,%!E-gr  
,fR/C  
/* {<J(*K*\Jo  
**FileAccess.java UU;U,q  
*//文件访问(定位,写) ab/^z0GT  
package NetFox; t_\;G~O9-M  
import java.io.*; *41 2)zEy  
D$&LCW#x  
*ke9/hO1i  
public class FileAccessI implements Serializable{ >x0)  
^W)h=49PN  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "u=U@1 ^  
RandomAccessFile oSavedFile; b>_eD-  
long nPos; -z6{!  
= 3("gScUj  
3{"MN=  
public FileAccessI() throws IOException K H&o`U(}  
{ R'e>YDC  
this("",0); <{"Jy)Uf  
} +`_Km5=  
C#3K.0a  
R|OY5@  
public FileAccessI(String sName,long nPos) throws IOException :.J]s<J(F  
{ "'zVwU  
oSavedFile = new RandomAccessFile(sName,"rw"); N |nZf5{  
this.nPos = nPos; u ^}R]:n  
oSavedFile.seek(nPos); +ia N[F$  
} {%PgR){qR  
{EL J!o[  
|tua*zEsS  
public synchronized int write(byte[] b,int nStart,int nLen) 2z+-vT%  
{ \7elqX`.yY  
int n = -1; \[MQJX,dn  
try{ h^aUVuL/  
oSavedFile.write(b,nStart,nLen); l+n0=^ Z  
n = nLen; /tqQAvj  
} p*l]I *x'<  
catch(IOException e) Ph Ep3o&"  
{ p+7ZGB  
e.printStackTrace (); PYPDK*Ie  
} wz1fl#WU  
g*a|QBj%  
Z7:TPY$b  
return n; B(/)mB  
} R.rxpJ+kU  
x=jS=3$8  
@Z{!T)#}j  
} %*Aq%,.={  
 XeRbn  
(Ymj  
/* ^}\!Sn  
**SiteInfoBean.java 1,pg7L8H  
*/ WAWy3i  
package NetFox; W2-1oS~ma  
d|Q_Z@;JF  
klON6<w  
public class SiteInfoBean { @5Zg![G  
n k@e#  
sn=_-uoU  
private String sSiteURL; //Site's URL _A5.  
private String sFilePath; //Saved File's Path k6|wiSyu  
private String sFileName; //Saved File's Name =U)e_q  
private int nSplitter; //Count of Splited Downloading File 5$;#=WAY  
NJ];Ck  
8/oO}SLF  
public SiteInfoBean() l:?w{'i$  
{//nSplitter的缺省值为5 gxf{/EjH  
//default value of nSplitter is 5 %V2A}78  
this("","","",5); hErO.ad1o  
} t.YY?5 l  
E%tGwbi7  
(I7s[  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p#DJow  
{ ,4`=gKn  
sSiteURL= sURL; IJz=SV  
sFilePath = sPath; }_ [Bp  
sFileName = sName; XA4miQn&  
this.nSplitter = nSpiltter; CUG3C  
-w#*~Q{'*  
8n`O{8:fi  
} ;(1Xb   
[<H'JsJl  
!caY  
public String getSSiteURL() )~CnDk}^R  
{ jXCSD@?]K  
return sSiteURL; {=)g?!zC  
} :,]*~Nl  
D <SLv,Y  
CQGq}.Jt!  
public void setSSiteURL(String value) Q`* v|Lp  
{ *W&}}iL  
sSiteURL = value; +* AdSzX  
} wx2 EMr   
/CW 0N@  
hI Q 2s  
public String getSFilePath() THcK,`lX@  
{ ? ^l{t4  
return sFilePath; %D9,Femt  
} +T|M U  
KbP( ;  
"jFRGgd79  
public void setSFilePath(String value) aUVJ\ ;V  
{ `$hna{e^n  
sFilePath = value; d=J$H<  
} S( nZ]QEG  
X_tc\}I]  
[h;&r"1  
public String getSFileName() m.|__L  
{ w4UaWT1J  
return sFileName; HC[)):S*  
} yCt,-mz!z  
dYP-QUM$7  
p#fd+  
public void setSFileName(String value) e_iXR#bZc  
{ ^P| K2at  
sFileName = value; p(J,fus  
} h0v4!`PQ-  
&y~EEh|  
N=hhuKt]  
public int getNSplitter() H/Wo~$  
{ Ny oRp  
return nSplitter; ;uK">L[u'  
} Q \E [py  
}% m:^*@$9  
:% o32  
public void setNSplitter(int nCount) N9s ,..  
{ W\W|v?r  
nSplitter = nCount; `VB]4i}u  
} LBs:O*;  
} ejID5NqG  
GNIZHyT(O  
 ,m^@S  
/* Xgs 31#K  
**Utility.java K}(0H[P  
*/ <l,Kg 'v  
package NetFox; *;]j#0  
k&kx%skz  
5m e|dvk  
public class Utility { 9*"Ae0ok1  
V6.w=6:`X  
MK*WStY  
public Utility() 6)QJms  
{ 5NT?A,r"  
p` '8M  
n qR8uL>  
} 5V{ B,T  
8,(FJ7OCT,  
//线程睡眠 f Cq  
public static void sleep(int nSecond) D02_ Jrg  
{ ee9nfvG-  
try{ $d[xSwang  
Thread.sleep(nSecond); +}u{{  
} Gl+Ql?|  
catch(Exception e) ?3vOc/2@  
{ iHp@R-g  
e.printStackTrace (); ATdK)gG  
} lM<SoC;[  
} 0d%p<c  
tk"+PTGJT  
//日志 4IW7^Pq`P  
public static void log(String sMsg) }E}b/ulg1  
{ pu"`*NL  
System.err.println(sMsg); 3O W) %  
} [J6*Q9B<V&  
y].vll8R  
AhjUFz  
public static void log(int sMsg) r-ldqj  
{ H,F/u&O  
System.err.println(sMsg); 0%9Nf!j  
} iyRB}[y  
} .Y?/J,Ch  
6@2 S*\&  
.7!n%Ks  
/* 7Z(F-B +j  
**TestMethod.java 1 >nl ]yO  
*/ )AX0x1I|E  
package NetFox; Pd,+= ML  
eTV%+  
Mk*&CNo3  
public class TestMethod { YRkp(}*!\  
$SP*hkU  
jf_0IE  
public TestMethod() e2SU)Tr%b  
{ ///xx/weblogic60b2_win.exe |+^-b}0  
try{ fCA/   
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *=-o0c  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :[#~,TW  
SiteFileFetch fileFetch = new SiteFileFetch(bean); OYWW<N+R2  
fileFetch.start(); | Q Y_ci  
} /<HEcB  
catch(Exception e){e.printStackTrace ();} NbD"O8dL~E  
X>n\@rTo  
rb/m;8v>  
} suh@  
,C#Mf@b  
N@M(Iw  
public static void main(String[] args) hLVS}HE2  
{ Wp0e?bK_  
new TestMethod(); @$5GxIw<l  
} > n~l\ fC  
} I[~EQ {Iz  
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