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http断点续传简单实现(java)

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/* >S:+&VN`M  
**SiteFileFetch.java ] {=qdgJ  
*/ `6o5[2V  
package NetFox; 3q`Uq`t4mR  
import java.io.*; 0#/Pc`z C  
import java.net.*; OdtS5:L  
!GtCOr\'  
13/U4-%b2  
public class SiteFileFetch extends Thread { &e5,\TQ  
d>x(Bj6  
&;$- &;  
SiteInfoBean siteInfoBean = null; //文件信息Bean -m Sf`1l0  
long[] nStartPos; //开始位置 ?wMS[Kj  
long[] nEndPos; //结束位置 "qw.{{:tf  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Ikgia:/-Z  
long nFileLength; //文件长度 42wZy|oqp  
boolean bFirst = true; //是否第一次取文件 -_BjzA|  
boolean bStop = false; //停止标志 3 /LW6W|  
File tmpFile; //文件下载的临时信息 p+Icq!aH5  
DataOutputStream output; //输出到文件的输出流 Klqte*!  
_&PF(/w  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 64f6D"."  
public SiteFileFetch(SiteInfoBean bean) throws IOException kj'  
{ d6~d)E  
siteInfoBean = bean; 7OLchf  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Lq{/r+tt/  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); J24H}^~na  
if(tmpFile.exists ()) >RKepV(X7  
{ (z X&feq  
bFirst = false; > `+lEob  
read_nPos(); fl<j]{*v  
} x!A5j $k0  
else >TS=tK  
{ vf['$um  
nStartPos = new long[bean.getNSplitter()]; :/i13FQ  
nEndPos = new long[bean.getNSplitter()]; TXfG@4~kC  
} qX*Xo[Xp  
Y,d|b V*FH  
 fG|+ !  
a>Xq   
} YtY.,H;  
FO?I}G22  
2w /qH4  
public void run() Q&?B^[N*Q  
{ {fu[&@XV  
//获得文件长度 ()yOK$"  
//分割文件 n16TQe"8  
//实例FileSplitterFetch +c\uBrlZQ;  
//启动FileSplitterFetch线程 mp17d$R-  
//等待子线程返回 i-Ri;E  
try{ T%1Kh'92  
if(bFirst) %YI!{  
{ n_-k <3  
nFileLength = getFileSize(); &Ef6'  
if(nFileLength == -1) ;V)94YT  
{ N"/be  
System.err.println("File Length is not known!"); @RLlkWGc  
} u %&4[zb  
else if(nFileLength == -2) rcG-V f@  
{ sys;Rz2  
System.err.println("File is not access!"); +yIO  
} 4mF=A$Q_/  
else <^B!.zQ  
{ o@:u:n+.  
for(int i=0;i<nStartPos.length;i++) 7' TXR[   
{ *wK7qS~VB2  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 3Tr}t.mt  
} vX"jL  
for(int i=0;i<nEndPos.length-1;i++) )\,hc$<=m  
{ r2>y !Q?  
nEndPos = nStartPos[i+1]; =!PUKa3f<  
} ~aRcA|`  
nEndPos[nEndPos.length-1] = nFileLength; Pna2IB+  
} SLI358]$<  
} [:-o;K\.-a  
%~YQl N  
($:JI3e[;  
//启动子线程 &?B\(?*  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dG'5: ,n/  
for(int i=0;i<nStartPos.length;i++) aW#_"Y}v'  
{ fO$~jxR.  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K9f7,/  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [bJAh ` I  
nStartPos,nEndPos,i); %#b+ =J  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kR|(hA,$N  
fileSplitterFetch.start(); T1pMe{  
} Q5qQ%cu  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ' C|yUsBC  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~yuj;9m3  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CF+:9PG  
nEndPos = " + nFileLength); ^LJ?GJ$g  
// fileSplitterFetch[nPos.length-1].start(); L~xzfO  
L[9]Ez$2+  
e8<[2J)P&  
//等待子线程结束 BFyVq  
//int count = 0; W L5!H.q  
//是否结束while循环 NX4}o&mDwn  
boolean breakWhile = false; Gn%gSH/  
-QUvd1S40  
bAqaf#}e  
while(!bStop) w/m ~#`a  
{ S[W|=(f9  
write_nPos(); r)SwV!b  
Utility.sleep(500); =1Mh %/y  
breakWhile = true; $I-i=:}g  
zSFqy'b.M-  
xlWTHn!j  
for(int i=0;i<nStartPos.length;i++) U i ~*]  
{ x9!vtrM\Zr  
if(!fileSplitterFetch.bDownOver) ,ZLg=  
{ 7`f',ZK%  
breakWhile = false; y-c2tF@'v  
break; &D 4Ci_6k  
} _GK3]F0  
} kGSB6  
if(breakWhile) H:HJHd"W  
break; L'Fy\K\  
A_WtmG_9  
* F T )`  
//count++; bqDHLoB\1  
//if(count>4) Hc{0O7  
// siteStop(); qSWnv`hL  
} pZ4]oK\*  
P$=Y5   
yy6?16@  
System.err.println("文件下载结束!"); "cUCB  
} vc_ 5!K%[  
catch(Exception e){e.printStackTrace ();} 2!35Tj"RFE  
} $xf{m9 8  
cSSrMYX2  
Z{ A)  
//获得文件长度 *OQr:e<}  
public long getFileSize() G:2m)0bW  
{ ;9hi2_luV  
int nFileLength = -1; P]G`Y>#$r  
try{ z@0*QZ.y 1  
URL url = new URL(siteInfoBean.getSSiteURL()); {~"6/L  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +L8 6 w7  
httpConnection.setRequestProperty("User-Agent","NetFox"); R2af>R  
I bd na9z7  
O0gLu1*1v  
int responseCode=httpConnection.getResponseCode(); iZ3%'~K<3J  
if(responseCode>=400) Q7 Clr{&  
{ C  +%&!Q  
processErrorCode(responseCode); zU'\r~c  
return -2; //-2 represent access is error &&;ol}W  
} .hxcx>%  
|E)Es!dr  
'MHbXFM  
String sHeader; ''f07R  
dik+BBu5z  
N@>,gm@UU  
for(int i=1;;i++) +)Pv6Zog[  
{ ^vjN$JB  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R;_U BQ)  
//Utility.log(in.readLine()); ,rp-`E5ap  
sHeader=httpConnection.getHeaderFieldKey(i); YEWHr>&Z  
if(sHeader!=null) w-%H\+J  
{ :_q   
if(sHeader.equals("Content-Length")) ~iZMV ?w  
{ btK| U  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;y7V-sf  
break; @]#0jiS  
} vRLkz4z   
} i~dW)7  
else ''Y}Q"  
break; ?5#Ng,8iT  
} 64^dy V,;  
} ;u'mSJI'  
catch(IOException e){e.printStackTrace ();} tZ]|3wp  
catch(Exception e){e.printStackTrace ();} *JX)q  
-BNlZgk-^  
|yi3y `f  
Utility.log(nFileLength); Ok+zUA[Wu  
'|b {  
q9RCXo>Y+1  
return nFileLength; d]OoJK9&&  
} bc"E=z  
}TZ5/zn.Dw  
B8^tIq  
//保存下载信息(文件指针位置) 3:i4DBp,i  
private void write_nPos() bUC-}  
{ fn zj@_{|  
try{ @xJ qG"  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9lA@ K[  
output.writeInt(nStartPos.length); PnsQ[}.  
for(int i=0;i<nStartPos.length;i++) E/ <[G?  
{ 8=!M0i  
// output.writeLong(nPos); ?=]`X=g 6  
output.writeLong(fileSplitterFetch.nStartPos); k[l+~5ix  
output.writeLong(fileSplitterFetch.nEndPos); h94SLj]  
} ~ySmN}3~'  
output.close(); r3l}I 6  
} _dj< xPO  
catch(IOException e){e.printStackTrace ();} jGzs; bE  
catch(Exception e){e.printStackTrace ();} *J!oV0#1  
} \`#;J?Y|`F  
2hV#3i  
{4 !%'~  
//读取保存的下载信息(文件指针位置) 22\Buk}?  
private void read_nPos() FDaHsiI:  
{ AC=cz!3iB  
try{ \^kyC1  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^lT$D8  
int nCount = input.readInt(); aW7{T6.,  
nStartPos = new long[nCount]; )^uLZMNaI  
nEndPos = new long[nCount]; $jb0/  
for(int i=0;i<nStartPos.length;i++) N:!XtYA<  
{ BJk:h-m [  
nStartPos = input.readLong(); 0}qij  
nEndPos = input.readLong(); />XfK,c-  
} Z&=K+P  
input.close(); BBw`8!  
} L`YnrDZK  
catch(IOException e){e.printStackTrace ();} .Lo$uKsW$l  
catch(Exception e){e.printStackTrace ();} I]>-~_  
} YH^_d3A;  
d3T|N\(DL  
(| Am  
private void processErrorCode(int nErrorCode) }$V]00 X  
{ 5j`"@C5;O  
System.err.println("Error Code : " + nErrorCode); $"T1W=;j9  
} p2PD';"  
[UquI "  
j3VM !/  
//停止文件下载 []0`>rVq  
public void siteStop() 6hYv  
{ 2](R}  
bStop = true; !&TbE@Xk  
for(int i=0;i<nStartPos.length;i++) U KF/v  
fileSplitterFetch.splitterStop(); qt}vM*0}V  
} 1w[G;$  
A6}M F  
} *Xt#04_  
}  r_]wa  
//负责部分文件的抓取 \~Zj](#  
**FileSplitterFetch.java RMDs~  
*/ m?xzx^xs/  
package NetFox; !,Wd$U K  
7|T<dfQk  
%96JH YcX  
import java.io.*; {$>*~.Wu  
import java.net.*; OekcU% C  
Kwfrh?  
WUAjb,eo  
public class FileSplitterFetch extends Thread { knpb$eX4  
X#5dd.RR  
_< 69d  
String sURL; //File URL "*#$$e53A  
long nStartPos; //File Snippet Start Position ppVjFCv0<  
long nEndPos; //File Snippet End Position BgD;"GD*W  
int nThreadID; //Thread's ID h|dVVCsN  
boolean bDownOver = false; //Downing is over jgYUS@}  
boolean bStop = false; //Stop identical d6<,R;)  
FileAccessI fileAccessI = null; //File Access interface u.0Z)j}N  
{gl-tRC3  
][:6En}  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _x z_D12  
{ E3.=|]W'  
this.sURL = sURL; JJ ,Fh .  
this.nStartPos = nStart; 0F`@/C1y55  
this.nEndPos = nEnd; E@"+w,x)  
nThreadID = id; ?AyG!F  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'rHkJ  
} Iqe4O~)  
%B3E9<9>U  
b0x9}  
public void run() Xgd!i}6Q  
{ {8Hrb^8!  
while(nStartPos < nEndPos && !bStop) 17H_>a\`  
{ 1 @E<5rp o  
:^3MN  
5h+g^{BE  
try{ M\,0<{  
URL url = new URL(sURL); 5)V J  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <X j:c2@  
httpConnection.setRequestProperty("User-Agent","NetFox"); WDY,?  
String sProperty = "bytes="+nStartPos+"-"; (p68Qe%OuG  
httpConnection.setRequestProperty("RANGE",sProperty); Lh"Je-x<<  
Utility.log(sProperty); @= 6}w_  
O\XN/R3  
,y,NVF  
InputStream input = httpConnection.getInputStream(); i+Px &9o<9  
//logResponseHead(httpConnection); h -+vM9j  
!zvKl;yT  
;_of'  
byte[] b = new byte[1024]; waQNX7Xdn  
int nRead; }Nl-3I.S^  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E92dSLhs5  
{ <y6M@(b  
nStartPos += fileAccessI.write(b,0,nRead); ;QW6Tgt11  
//if(nThreadID == 1) v(FO8*5DZ  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Dq*>+1eW2  
} ! s?vj <  
'7 6}6G%  
nBaY|  
Utility.log("Thread " + nThreadID + " is over!"); q*@7A6:FV>  
bDownOver = true; YQ 4;X8I`r  
//nPos = fileAccessI.write (b,0,nRead); 9,82Uta  
} ??aOr*%  
catch(Exception e){e.printStackTrace ();} <QugV3e  
} !a ~>;+  
} P00d#6hPJ  
7}%3Aw6]S  
^g~Asz5]  
//打印回应的头信息 -}MWA>an8  
public void logResponseHead(HttpURLConnection con) C:_!zY'z  
{ %xyt4}-)m  
for(int i=1;;i++) aoco'BR F  
{ _z)G!_7.>\  
String header=con.getHeaderFieldKey(i); |`U^+Nf  
if(header!=null) nC qUg_{D  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,78 QLh9:  
Utility.log(header+" : "+con.getHeaderField(header)); my[)/'  
else niFX8%<hP  
break; UALwr>+VJ  
} WA8Qt\Q  
} 6WgGewn  
/+"BU-aQk  
>wdR4!x!?  
public void splitterStop() `{N0+n  
{ ZJ 8~f  
bStop = true; W.-[ceM  
} <!Nj2>  
rV"<1y:g  
,@/b7BVv  
} `U#*O+S-^  
PGP9-M  
"T<Q#^m  
/* |5Mhrb4.  
**FileAccess.java 3:Y ZC9  
*//文件访问(定位,写) R8c1~'  
package NetFox; :v* _Ay  
import java.io.*; Ol~sCr  
s IY`H^  
y!1%Kqx1,n  
public class FileAccessI implements Serializable{ f /&Dy'OV7  
:w#Zs)N  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ya5;C"   
RandomAccessFile oSavedFile; pTST\0?  
long nPos; {Rc/Ten  
&%>l9~F'~  
37v!:xF!  
public FileAccessI() throws IOException gJ+MoAM"  
{ .2C}8GGC'  
this("",0); gv r "F  
} >E#| H6gx  
y)"aQJ>  
Qa5<go{  
public FileAccessI(String sName,long nPos) throws IOException cnnlEw/&  
{ 3:PBVt=  
oSavedFile = new RandomAccessFile(sName,"rw"); iJZqAfG{m?  
this.nPos = nPos; ;jfjRcU  
oSavedFile.seek(nPos); 0X~   
} TixH Ehw  
gkI(B2,/  
mSY;hJi  
public synchronized int write(byte[] b,int nStart,int nLen) S s@\'K3e  
{  PQa {5"  
int n = -1; KX"?3#U#Fm  
try{ ;? '`XB!  
oSavedFile.write(b,nStart,nLen); %q;3b fq@N  
n = nLen; R."<he ;  
} {[jcT>.3j  
catch(IOException e) 5H6m{ng  
{ 0F1 a  
e.printStackTrace (); drBWo|/  
} 54JZEc  
lV?rC z  
)xiic3F  
return n; H\Y.l,^  
} )p~\lM}?d  
d0Py[37V  
7Z0 )k9*  
} ~Hd{+0  
k v,'9z  
`ihlKFX  
/* `pn]jpW9  
**SiteInfoBean.java ua/A &XQx  
*/ ecA:y!N  
package NetFox; g:dw%h  
mv/'H^"[_  
`4'v)!?  
public class SiteInfoBean { NN\% X3ri"  
lf4-Ci*X  
k_r12Bu  
private String sSiteURL; //Site's URL pD9*WKEf*  
private String sFilePath; //Saved File's Path yc8iT`  
private String sFileName; //Saved File's Name (*;b\h  
private int nSplitter; //Count of Splited Downloading File we4e>)  
8Focs p2  
TbXp%O:[W  
public SiteInfoBean() )TP 1i  
{//nSplitter的缺省值为5 -;a}'1HOE  
//default value of nSplitter is 5 Ett%Y*D+J  
this("","","",5); (x@|6Sb  
} /1zi(z   
\L}Soe'  
f>s3Q\+  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !e?=I  
{ *TfXMN ?w  
sSiteURL= sURL; awB1ryrOF  
sFilePath = sPath; 89v9BWF  
sFileName = sName; DxdiXf[j  
this.nSplitter = nSpiltter; j5Vyo>  
:7K cD\fCj  
\zR@FOl`q  
} ()6(eRGJ  
{CG%$rh  
O]DZb+O"  
public String getSSiteURL() Zgkk%3'^'  
{ "EQ`Q=8  
return sSiteURL; cgNK67"(  
} v(W$\XH  
JfxD-9U^>u  
hk3}}jc  
public void setSSiteURL(String value) 3BAls+<p o  
{ q!\K!W\  
sSiteURL = value; \rn:/  
} s$4!?b$tw  
)[|TxXz d  
{" woBOaA  
public String getSFilePath() (n;#Z,  
{ jAB~XaT,  
return sFilePath; o9(:m   
} Wz)s#  
_Jx.?8  
T?4MFx#  
public void setSFilePath(String value) $ jWe!]ASU  
{ 2 DJs '"8  
sFilePath = value; 7m~.V[l1  
} \XFF(  
yDg`9q.ckm  
eU&[^  
public String getSFileName() 2a'b}<|[(  
{ ekND>Qjj  
return sFileName; 8iaP(*J  
} rz+)z:u  
l tE`  
.|^L\L(!  
public void setSFileName(String value) HJ?p,V q5_  
{ -f@~{rK.L  
sFileName = value; &\#If:  
} I(y:Td  
4/vQ/>c2j  
.;&c<c|  
public int getNSplitter() lK;|ciq"c7  
{ ;|*o^9q  
return nSplitter; F`IV9qv  
} |re)]%A?Fu  
1 41@$mMzE  
P /|2s  
public void setNSplitter(int nCount) J5e  
{ [vh&o-6  
nSplitter = nCount; c}v>Mx  
} ZFpi'u.&  
} )65 o  
<Dojl #  
5V5Nx(31i  
/* .`*h2  
**Utility.java Y` t-Bg!~  
*/ Teh _  
package NetFox; -X BD WV  
i,|2F9YH  
`d]D=DtH  
public class Utility { ;}"!|  
vncLB&@7  
DdDwMq  
public Utility() @c,Qj$\1  
{ fGS5{dti  
&v9*D`7L  
5q4sxY9T  
} WX<),u2@  
+)YU/41W  
//线程睡眠 tk=~b} 8  
public static void sleep(int nSecond) z0|%h?N  
{ 'b(V8x  
try{ 4UP#~  
Thread.sleep(nSecond); 6?\X)qBI  
} h[H FZv~{  
catch(Exception e) ?=$=c8xw  
{ (jhDO7  
e.printStackTrace (); j0P+<@y  
} zv/owK  
} Y,0D+sO4  
K@d,8[  
//日志 %Y!31oC#  
public static void log(String sMsg) |hGi8  
{ kD1[6cJ!=.  
System.err.println(sMsg); +9Vp<(  
} kq +`.  
p+6L qk<  
P(h[QAM  
public static void log(int sMsg) ^}Vx5[  
{ EhJpJb[Z  
System.err.println(sMsg); -aj) _.d  
} 3s25Rps  
} h|m>JDxn  
\ k&(D*u  
o+-G@ 16  
/* Nr6[w|Tzd  
**TestMethod.java ~t0\Q; @($  
*/ *F[;D7sZ~  
package NetFox; 3pQ^vbQ"  
Qmbl_#  
9qe<bds1  
public class TestMethod { JSKAlw  
+E5EOo{ `|  
W[ZW=c  
public TestMethod() 2g'o5B\ *  
{ ///xx/weblogic60b2_win.exe /D@(o`a  
try{ )Pj8{.t4  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lxSCN6  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #\DKU@|h  
SiteFileFetch fileFetch = new SiteFileFetch(bean); c ow]qe6K  
fileFetch.start(); "WPFZw:9  
} WBOebv  
catch(Exception e){e.printStackTrace ();} BBkYc:B=SA  
o]gS=iLp  
UB5X2uBv  
} [*i6?5}-  
znVao %b  
Fkq;Q  
public static void main(String[] args) *21foBfqh  
{ 7R4xJ H  
new TestMethod(); .|d2s  
} <OR f{  
} -XcX1_  
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