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http断点续传简单实现(java)

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/* p?,T%G+gqO  
**SiteFileFetch.java 0RF<:9@x2  
*/ wDt9Lf O  
package NetFox; 82P#C4c+d  
import java.io.*; $_+.D`vx`  
import java.net.*; )Im3';qt  
_edT+r>+  
Q`HG_n@?  
public class SiteFileFetch extends Thread { 7Um3m yXU  
T]lVwj  
+![\7  
SiteInfoBean siteInfoBean = null; //文件信息Bean l<UJ@XID$  
long[] nStartPos; //开始位置 7J|e L yj  
long[] nEndPos; //结束位置 -~TgA*_5]  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 |>v8yS5  
long nFileLength; //文件长度 se S)`@n  
boolean bFirst = true; //是否第一次取文件 i:sb_U+M  
boolean bStop = false; //停止标志 eMOnzW|h  
File tmpFile; //文件下载的临时信息 }kF*I@:g  
DataOutputStream output; //输出到文件的输出流 mNQ*YCq.  
5;[h&jH  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ^$;5ZkQy  
public SiteFileFetch(SiteInfoBean bean) throws IOException !=p^@N7  
{ .B_a3K4'{^  
siteInfoBean = bean; YPmgR]=6  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); :^J'_  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); EMw biGV  
if(tmpFile.exists ()) fctVJ{?  
{ V_P,~!  
bFirst = false; G|LcTV  
read_nPos(); u;/<uV3  
} KY9&Ky+2B  
else s-e<&*D[  
{ %0lJ(hm  
nStartPos = new long[bean.getNSplitter()]; yL"pzD`[H  
nEndPos = new long[bean.getNSplitter()]; gPY Cw?zQ  
} icXeB_&cS  
gVN&?`k*?  
F2C v,&'  
)(DX]Tr`  
}  c.Do b?5  
!3Ed0h]Bfa  
X0BBJ(e  
public void run() e) kVS}e?  
{ [' cq  
//获得文件长度 (k<__W c_t  
//分割文件 (T8dh|  
//实例FileSplitterFetch X@^"@  
//启动FileSplitterFetch线程 N6uKFQL:{  
//等待子线程返回 VN >X/  
try{ Z:Nm9m  
if(bFirst) k(R&`  
{ \Z/# s;c,4  
nFileLength = getFileSize(); i1-wzI  
if(nFileLength == -1) !--A"  
{ r=:o$e  
System.err.println("File Length is not known!"); g6(u6%MD  
} zf?U q  
else if(nFileLength == -2) ?gl[ =N V  
{ 1'YksuYx6f  
System.err.println("File is not access!"); l3;MjNB^V  
} ky{-NrK  
else 8BggK6X  
{ ?vocI  
for(int i=0;i<nStartPos.length;i++) )jm u*D5N  
{  rhO 8v  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); {"@E_{\  
} (7?jjH^4  
for(int i=0;i<nEndPos.length-1;i++) I>%@[h,+  
{ '/ GZ,~q  
nEndPos = nStartPos[i+1]; O`2hTY\  
} +HfZs"x  
nEndPos[nEndPos.length-1] = nFileLength; ehr,+GX  
} ALl0(<u67  
} 5}he)2*uD  
;eiqzdP  
)NCSO b  
//启动子线程 [LrA_N  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L7 g4'  
for(int i=0;i<nStartPos.length;i++) XZ1WY(  
{ JB(P-Y#yyA  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WG(%Pkowv  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), u{(-`Al}L  
nStartPos,nEndPos,i); G&v. cF#Y'  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VQ'DNv| 9  
fileSplitterFetch.start(); h$I 2T  
} TI^M9;b  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jjU("b=  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZY{zFg9  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^laf!kIP  
nEndPos = " + nFileLength); $ZfoJR]%  
// fileSplitterFetch[nPos.length-1].start(); RMO6kbfP  
c(!8L\69V}  
EP}NT)z,{  
//等待子线程结束 2` j#eB1  
//int count = 0; s5D<c'-  
//是否结束while循环 Q(7M_2e7  
boolean breakWhile = false; )ZQML0}P;  
[;8vO=Z  
zx=AT  
while(!bStop) M`gr*p  
{ Yn1CU  
write_nPos(); Fc.1)yh.  
Utility.sleep(500); V.12  
breakWhile = true; u<a =TPAU  
4&/m>%r  
EE[JXoke  
for(int i=0;i<nStartPos.length;i++) [SA$d`B/  
{ \<4Hp_2?  
if(!fileSplitterFetch.bDownOver) J<=k [Q  
{ iJem9XXb  
breakWhile = false; oar`xH$C  
break; =EdLffU[J  
} XbL\l  
} /8tF7Mmr  
if(breakWhile) `Wy8g?d;bn  
break; 6<+8[o  
kr6^6I.  
H_+F~P5RC  
//count++; 84UI)nE:Q  
//if(count>4) ?~s23%E  
// siteStop(); _M9-n  
} 7l|D!`BS  
Lyj0$wbH`  
3f^~mTY9>]  
System.err.println("文件下载结束!"); _$YT*o@0J  
} [t}$W*hY  
catch(Exception e){e.printStackTrace ();} [Csv/  
} %9P)Okq  
CxW-lU3G`  
 cnwpd%]o  
//获得文件长度 3^J~ts{*  
public long getFileSize() X'KkIo :  
{ 9;k!dM  
int nFileLength = -1; ! fSM6Vo  
try{ Bq)aA)gF  
URL url = new URL(siteInfoBean.getSSiteURL()); d:1TSJff%/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OJ Y_u[  
httpConnection.setRequestProperty("User-Agent","NetFox"); 2E d  
X__>r ?oJ  
6pi^rpo  
int responseCode=httpConnection.getResponseCode(); x0dO ^D  
if(responseCode>=400) v9 K{oB  
{ ~[d|:]  
processErrorCode(responseCode); m_n*_tX  
return -2; //-2 represent access is error 6fr@y=s2:  
} 'AjDB:Mt$  
Bm&%N?9  
\"^.>+  
String sHeader; .ECT  
?Pw(  
!;ipLC;e}  
for(int i=1;;i++) "8|a4Y+F  
{ aO]FQ#l2b  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =f*Wj\  
//Utility.log(in.readLine()); rS/}!|uAu  
sHeader=httpConnection.getHeaderFieldKey(i); >:yU bo)  
if(sHeader!=null) hJcN*2\:  
{ x&PVsXdt5m  
if(sHeader.equals("Content-Length")) g<"k\qs7  
{ e$+/;MRq  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qqR8E&Y{  
break; l{b*YUsz>  
} :4, OA  
} DHnu F@M  
else QY]G+3W  
break; 3vK,vu q  
} @p}"B9h*^  
} (iw)C)t*u  
catch(IOException e){e.printStackTrace ();} n'-?CMH`  
catch(Exception e){e.printStackTrace ();} =TzmhX5  
uh_ 2yw_  
X_nxC6[m%  
Utility.log(nFileLength); Y']D_\y  
= rLL5<  
1 6N+  
return nFileLength; WMw]W&  
} MU/3**zoW  
_RcFV  
!^EdB}@yS  
//保存下载信息(文件指针位置) ]@D#<[5\  
private void write_nPos() %Z#s9QC  
{ 39+6ZTqx  
try{ g.re`m|Aj  
output = new DataOutputStream(new FileOutputStream(tmpFile)); I/ q>c2Pw$  
output.writeInt(nStartPos.length); ^&mJDRe  
for(int i=0;i<nStartPos.length;i++) %Qc5_of  
{ #^FDFl  
// output.writeLong(nPos); B}YpIb]d  
output.writeLong(fileSplitterFetch.nStartPos); ozr82  
output.writeLong(fileSplitterFetch.nEndPos); |`50Tf\J  
} @&G< Np`  
output.close(); ZC\&n4~7  
} k-uwK-B}v+  
catch(IOException e){e.printStackTrace ();} rIg5Wcd  
catch(Exception e){e.printStackTrace ();} o : t z_5  
} Xob,jo}a  
}#h>*+Q  
Q5:8$ C}+  
//读取保存的下载信息(文件指针位置) />,Tq!i\4}  
private void read_nPos() SpB\kC"K  
{ =Hs[peO*  
try{ s/"?P/R  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6HyndB^  
int nCount = input.readInt(); ">pt, QV  
nStartPos = new long[nCount]; wC~ra:/?:7  
nEndPos = new long[nCount]; 4tb y N  
for(int i=0;i<nStartPos.length;i++) _poe{@h!  
{ ^XIVWf#`H  
nStartPos = input.readLong(); ;=?f0z<  
nEndPos = input.readLong(); dmkd.aP4  
} Zoi\r  
input.close(); l1h;ng6  
} s^n}m#T  
catch(IOException e){e.printStackTrace ();} k]<E1 c/  
catch(Exception e){e.printStackTrace ();} uuA q\YZy/  
} :172I1|7  
2W_p)8t> b  
DG!H8^  
private void processErrorCode(int nErrorCode) S|pMX87R  
{ \~:Uj~  
System.err.println("Error Code : " + nErrorCode); Vif0z*\e{  
} ;GgW&*|  
0Ek + }`  
/s\_"p  
//停止文件下载 2unaK<1s  
public void siteStop() MzY~-74aF  
{ dD Zds k+!  
bStop = true; P})Iwk|Z  
for(int i=0;i<nStartPos.length;i++) 7K|: 7e(  
fileSplitterFetch.splitterStop(); F{g^4  
{4@+ 2)l  
LXm5f;  
} d\R]>  
} w!=Fi  
//负责部分文件的抓取 p? dXs^ c  
**FileSplitterFetch.java I,:R~^qJ8v  
*/ G q" [5r"  
package NetFox; EPZ^I)  
P9\!JH!  
.K n)sD1  
import java.io.*; `a!:-.:v  
import java.net.*; !p4y@U{  
]ZB^Hi_  
6^oQ8unmS  
public class FileSplitterFetch extends Thread { ZDI%?.U  
soH M5<U  
0(Hhb#WDh\  
String sURL; //File URL eoC@b/F4  
long nStartPos; //File Snippet Start Position `Z}7G@ol  
long nEndPos; //File Snippet End Position pnvHh0ck_  
int nThreadID; //Thread's ID )<kI d4E  
boolean bDownOver = false; //Downing is over kbxy^4"X  
boolean bStop = false; //Stop identical @LzqQ [  
FileAccessI fileAccessI = null; //File Access interface Zy>iaG9}  
i09w(k?  
Gg\805L@  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wQ4IQ!  
{ #s!q(Rc  
this.sURL = sURL; q Z,7q  
this.nStartPos = nStart; \1AtB c&  
this.nEndPos = nEnd; epWO}@ b a  
nThreadID = id; /lC&'hT  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sUfYEVjr  
} }[[  
vu&%e\gM  
_ 2WG6y;  
public void run() z g@,s"`>  
{ Ls<.&3X2  
while(nStartPos < nEndPos && !bStop) nY#V~^|  
{ wO&edZ]zb^  
wClX3l>y  
M%3 \]&  
try{ hr+,-j  
URL url = new URL(sURL); x}`]9XQ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oPX `/ X#  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^st.bzg+[  
String sProperty = "bytes="+nStartPos+"-"; 0u?{"xH{+}  
httpConnection.setRequestProperty("RANGE",sProperty); 2f%G`4/p  
Utility.log(sProperty); 6%p$C oR  
)]=1W  
FAS+*G Fz  
InputStream input = httpConnection.getInputStream(); <h$Nh0  
//logResponseHead(httpConnection); 1;\A./FVv  
tj:Q]]\M  
b)SU8z!NV&  
byte[] b = new byte[1024]; N34.Bt  
int nRead; rc*iL   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1|?8g2Vf  
{ Koi  
nStartPos += fileAccessI.write(b,0,nRead); aX oD{zA  
//if(nThreadID == 1) 6O`s&T,t  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D['z/r6F  
} W-QBC- 3  
Y1?"Ut  
/-#1ys#F=  
Utility.log("Thread " + nThreadID + " is over!"); =aWj+ggd@  
bDownOver = true; GJUorj&  
//nPos = fileAccessI.write (b,0,nRead); ,s%1#cbR  
} e~#"#?  
catch(Exception e){e.printStackTrace ();} Nn"[GB  
} ,~R`@5+  
} BVKr 2v  
pzo9?/-  
>y2;sJ4]D%  
//打印回应的头信息 SNV[KdvP*  
public void logResponseHead(HttpURLConnection con) uB(16|W>S  
{ x2#5"/~4  
for(int i=1;;i++) arCi$:-z@  
{ !J5k?J&{=  
String header=con.getHeaderFieldKey(i); X#qm wcF  
if(header!=null) J3]W2m2Zw  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ECO4ut.d  
Utility.log(header+" : "+con.getHeaderField(header)); F/"Q0%(m  
else "Ih>>|r  
break; V)$y  
} 3f u*{8.XZ  
} ^J?ExMu  
'f#i@$|]  
+<G |Ru-  
public void splitterStop() p19[qy~.  
{ F-\Swbx+  
bStop = true; 3'd(=hJ45$  
} ){AtV&{$  
pJ` M5pF  
A9*( O)  
} [j6EzMN  
4Y):d!'b  
W"m\|x  
/* A@8Ot-t:\2  
**FileAccess.java di@4'$5#  
*//文件访问(定位,写) \m3'4#  
package NetFox; rjmKe*_1V  
import java.io.*; y:U'3G-  
WIytgM  
4%8}vCs  
public class FileAccessI implements Serializable{ LvWl*:z  
,0'Yj?U>  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >m}U|#;W  
RandomAccessFile oSavedFile; K[wOK  
long nPos; |x2 +O  
1'skCR|!<  
^i"C%8  
public FileAccessI() throws IOException 9,?\hBEu  
{ vybQ}dscn  
this("",0); KGMX >t'  
} `y&d  
? m$uqi  
|-WoR u  
public FileAccessI(String sName,long nPos) throws IOException dDuT,zP  
{ h8b*=oq  
oSavedFile = new RandomAccessFile(sName,"rw"); s6#@S4^=\  
this.nPos = nPos; ZS&n,<a5L}  
oSavedFile.seek(nPos); -=W"  
} dXkgWLI~  
"4VC:"$f  
'bH',X8gF  
public synchronized int write(byte[] b,int nStart,int nLen)  0p8Z l  
{ uCA! L)$  
int n = -1; @/S6P-4  
try{ IrAc&Ehul  
oSavedFile.write(b,nStart,nLen); '}3m('u  
n = nLen; T6X%.tR>`  
} 45Z"U<I,9  
catch(IOException e) 8+m[ %5lu  
{ XA cpLj]  
e.printStackTrace (); ep"YGx  
} 64Ot`=A"  
lpW|GFG  
h)%}O.ueB  
return n; Wvhg:vup  
} }uI(D&?+h  
A),nkw0X  
so* lV  
} GZL{~7n  
J`6X6YZ  
~~U2Sr  
/* ?e? mg  
**SiteInfoBean.java Hx}K w S  
*/ -qki^!Y?  
package NetFox; |E\0Rv{H3  
aZ$$a+  
3pxm0|  
public class SiteInfoBean { sZ,MNF8i  
_n.2'  
LPjsR=xi  
private String sSiteURL; //Site's URL DVu_KT[Hd  
private String sFilePath; //Saved File's Path +O< 0q"E  
private String sFileName; //Saved File's Name !B=Oc!e=K  
private int nSplitter; //Count of Splited Downloading File ;WQ@dC  
"J0,SFu:  
9m2_zfO[ w  
public SiteInfoBean() 8\-Q(9q(  
{//nSplitter的缺省值为5 IAr  
//default value of nSplitter is 5 HaP0;9q  
this("","","",5); {HV$hU+_)Q  
} SZOcFmC?  
P!?Je/ Tz]  
8S&Kf>D  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q!iMc  
{ L  lP  
sSiteURL= sURL; Qm| Q0u   
sFilePath = sPath; '4PAH2&n  
sFileName = sName; nwwKef(  
this.nSplitter = nSpiltter; #+V5$  
[OI&_WIw  
zw{cli&S  
} #1MEmt  
,2F4S5F~rC  
s*R \!L  
public String getSSiteURL() j@0/\:1(U  
{ X-oHQu5  
return sSiteURL; !Jo3>!,j  
} #4(/#K 1j  
q&IO9/[dk  
20hF2V  
public void setSSiteURL(String value) sSLs%)e|:  
{ Mis t,H7  
sSiteURL = value; 2#4_ /5(j*  
} )oOcV%  
@MfuV4*  
zcrLd={  
public String getSFilePath() -e=p*7']  
{ LGN,8v<W(  
return sFilePath; ,}M@Am0~  
} ETP}mo  
({3hX"C@Q  
VjU;[  
public void setSFilePath(String value) =RR225  
{ )!1; =   
sFilePath = value; G"CV S@  
} Sd;/yC8  
0G/VbS  
Jtj_R l !  
public String getSFileName() W_EM k  
{ $!c)%qDq  
return sFileName; C24[brf  
} gY AXUM,  
8?S32Gdu  
Q]_3 #_'  
public void setSFileName(String value) zr9o  
{ V/Hjd`n)`i  
sFileName = value; |]a =He;  
} @Taj++ua  
)u7*YlU\I  
Wxl^f?I`:  
public int getNSplitter() QDlEby m  
{ n{F$,a  
return nSplitter; ~mc7O  
} yD iL  
q<>  
cq'opjLf5  
public void setNSplitter(int nCount) q!#e2Dx  
{ vjG: 1|*e  
nSplitter = nCount; Sf>R7.lpP  
} ?PNG@OK  
} =z'w-ARy  
MnvFmYgxA  
ZF :e6em  
/* "|CzQ&e  
**Utility.java ^(I4Do~}  
*/ mrDIt4$D  
package NetFox; 66<3zadJZU  
SCk2D!u  
l-"c-2-!  
public class Utility { "J]_B  
nAn/Vu  
o+W5xHe^1  
public Utility() ]trVlmZXH}  
{ ReOp,A/y  
f[3DKA  
`r+"2.z*  
} 27*u^N*z@  
jw$3cwddH  
//线程睡眠 4C^;lK  
public static void sleep(int nSecond) P"0S94o:5J  
{ V,bfD3S3  
try{ THirh6  
Thread.sleep(nSecond); b:.aZ7+4  
} &eV& +j  
catch(Exception e) W)jO 4,eO  
{ SU OuayE  
e.printStackTrace (); 9I8{2]  
} >N>WOLbb7(  
} 9l2,:EQ*  
&^e%gU8!\  
//日志 #%k!`?^fbK  
public static void log(String sMsg) *6~ODiB  
{ F)/}Q[o8  
System.err.println(sMsg); JqTkNKi/s  
} &P&LjHFK  
V6"<lK8"  
#|fa/kb~  
public static void log(int sMsg) vCT5do"C&  
{ fk)ts,p?  
System.err.println(sMsg); tS,nO:+x  
} |du@iA]dP  
} *,hS-  
 t4pc2b  
Dt)\q^bH)  
/* N+x0"~T}I  
**TestMethod.java 3DnlXH(h1  
*/ 9^h\vR|]S  
package NetFox; mD-qJ6AM  
<`*}$Zh  
Pk[:+. f(  
public class TestMethod { vJDK]p<}  
obRR))  
U>6MT@\  
public TestMethod() p+U}oC  
{ ///xx/weblogic60b2_win.exe Tx?,]c,(u  
try{ 1a 3rA  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T6JN@:8  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f>ohu^bd  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Zws[}G"7h  
fileFetch.start(); LAeJz_9U  
} g1VdP[Y#  
catch(Exception e){e.printStackTrace ();} emOd<C1A  
x/Se /C  
[H z_x(t26  
} 0ZPwEP  
9tsI1]1[m  
Mit,X  
public static void main(String[] args) V %'`nJ!  
{ XVAy uuTg\  
new TestMethod(); 4>nY't;0  
} PHl{pE*  
} G$pTTT6#  
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