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http断点续传简单实现(java)

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/* `I8^QcP  
**SiteFileFetch.java .A\\v6@  
*/ hU 7fZl%yl  
package NetFox; ]M(mq`K  
import java.io.*; sZ"U=6R  
import java.net.*; H g`{9v  
mM} Ukmy  
!XG&=Rd?  
public class SiteFileFetch extends Thread { @vYmkF`  
'pY;]^M  
0s|LK  
SiteInfoBean siteInfoBean = null; //文件信息Bean -;\+uV  
long[] nStartPos; //开始位置 QYgN39gp  
long[] nEndPos; //结束位置 EYxRw  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 5}xni  
long nFileLength; //文件长度 xacLlX+  
boolean bFirst = true; //是否第一次取文件 wzPw; xuG  
boolean bStop = false; //停止标志 igrog  
File tmpFile; //文件下载的临时信息 X|`,AK Jit  
DataOutputStream output; //输出到文件的输出流 ~ n^G<iXLp  
0f%:OU5Y  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ;_/q>DR>,3  
public SiteFileFetch(SiteInfoBean bean) throws IOException Sx)Il~ x  
{ {z/^X<T  
siteInfoBean = bean; 9.zQ<k2  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); B)]{]z0+`  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 4nH91Z9=  
if(tmpFile.exists ()) *Qx|5L!_  
{ 9ET+k(wI@  
bFirst = false; " ^baiN@ac  
read_nPos(); i=UTc1  
} WcwW@cY7\  
else y8vH?^:%<  
{ P\4tK<P|  
nStartPos = new long[bean.getNSplitter()]; hIQ[:f  
nEndPos = new long[bean.getNSplitter()]; n u8j_grW  
} q#&#*6 )B  
`b")Bx|  
b8Rh|"J)d  
2A}uqaF  
} =>0M3 Qh{  
c^Jgr(Ow  
0@K:Tq-mF  
public void run() B21AcE  
{ g]<Z]R`  
//获得文件长度 OgN1{vRFx  
//分割文件 L4pjh&+8  
//实例FileSplitterFetch (oitCIV  
//启动FileSplitterFetch线程 G>,nZ/,A{  
//等待子线程返回 W)!{U(X  
try{ 5@D7/$bLp  
if(bFirst) $xtE+EV.p  
{ 1m`tqlFU9  
nFileLength = getFileSize(); 7~ese+\smG  
if(nFileLength == -1) o,Zng4NY  
{ i!W8Q$V  
System.err.println("File Length is not known!"); ]cqZ!4?_  
} z|]oM#Gt  
else if(nFileLength == -2) ~}IvY?! ;  
{ SxZ^ "\H  
System.err.println("File is not access!"); %<C G|]W  
} G 0QXf  
else DIqT>HHZ  
{ NhoS7 y(  
for(int i=0;i<nStartPos.length;i++) fuD1U}c  
{ .Spi$>v  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); y8hg8J|  
} .x!7  
for(int i=0;i<nEndPos.length-1;i++) gZ"{{#:}  
{ >3`ctbe  
nEndPos = nStartPos[i+1]; nqxq@.L2  
} VuMDV6^Z  
nEndPos[nEndPos.length-1] = nFileLength; sRyw\v-=P  
} 2v9s@k/k)6  
} K%c ATA3  
"56?/ jF  
+Bq}>  
//启动子线程 gLaO#cQ%  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =3sldKL&F  
for(int i=0;i<nStartPos.length;i++) ,AbKxT f2  
{ :@>br+S  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D d# SUQ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), SZ2q}[o`R  
nStartPos,nEndPos,i); } C{}oLz  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q)6wkY+!  
fileSplitterFetch.start(); d0A\#H_&  
} \ ~LU 'j  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sK 1m9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [B ~zoB(  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L.0} UXd  
nEndPos = " + nFileLength); 3 2 1={\X  
// fileSplitterFetch[nPos.length-1].start(); 2Ph7qEBQ22  
P\X=*  
~6:LUM  
//等待子线程结束 {{]=zt|69  
//int count = 0; /y](mu"!  
//是否结束while循环 QK?2E   
boolean breakWhile = false; ?St=7a(D  
YoF\ MT]W  
!HR2Rfl  
while(!bStop) 38U5^`  
{ 2u~c/JryN  
write_nPos(); Xrj(,|  
Utility.sleep(500); |.8d,!5w}  
breakWhile = true; kg?T$}O  
11B{gUv.]  
ll(e,9.D  
for(int i=0;i<nStartPos.length;i++)  mF*?e/  
{ A)RI:?+  
if(!fileSplitterFetch.bDownOver) 6t_ 3%{  
{ DYAwQ"i;6  
breakWhile = false; uq|vNLW26  
break; Lov.E3S6;  
} %89" A'g  
} P )t]bS  
if(breakWhile) n~,]KdU]  
break; 8sR  
EFRZ% Y  
B;z>Dd,Y_x  
//count++; #0?"J)  
//if(count>4) Zr.\`mG4f  
// siteStop(); vNC$f(cQ  
} h{W$ fZc<  
Y|m_qB^_  
qD(fYOX{C  
System.err.println("文件下载结束!"); rysP)e  
} )e|$K= D  
catch(Exception e){e.printStackTrace ();} k+WO &g*|  
} FtFv<UV  
C`NBHRa>  
s`Yu"s 8}4  
//获得文件长度 iJ`%yg,  
public long getFileSize() N?a1sdR  
{ N"YK@)*Q  
int nFileLength = -1; :jk)(=^  
try{ ~{7zm"jN  
URL url = new URL(siteInfoBean.getSSiteURL()); {WYu 0J@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hF{x')(#l  
httpConnection.setRequestProperty("User-Agent","NetFox"); jU]]:S4xD/  
`P^u:  
{k_ PMl0G  
int responseCode=httpConnection.getResponseCode(); o%V @D'w  
if(responseCode>=400) d,Cz-.'sOf  
{ 0a2$P+p  
processErrorCode(responseCode); &TP:yA[  
return -2; //-2 represent access is error F@=e2e 4  
} }[>RxHd  
io9y; S"+  
VM-qVd-  
String sHeader; _=|nOj39  
s6uF5]M;2  
)|U_Z"0H^  
for(int i=1;;i++) ,zAK3d&hj  
{ bU;}!iVc]  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Mvy6"Q:  
//Utility.log(in.readLine()); +=ZWau   
sHeader=httpConnection.getHeaderFieldKey(i); :"M9*XeHO  
if(sHeader!=null) -Q<z1vz  
{ FF%\g J  
if(sHeader.equals("Content-Length")) OwG6i|q  
{ jzl?e[qPA  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); aUypt(dv  
break; .mvB99P{<  
} :`+|'*b(A  
} Smq r q  
else IvEMg2f}  
break; hH <6E  
} 94~"U5oQ:  
} p!HPp Ef+#  
catch(IOException e){e.printStackTrace ();} "XGD:>Q.  
catch(Exception e){e.printStackTrace ();} W<\kf4Y  
r+t ,J|V  
|rr$U  
Utility.log(nFileLength); "bD+/\ z  
@T<ad7g-2J  
c@RT$Q9j  
return nFileLength; opm?':Qst  
} p+orBw3  
9U#\nXM  
Z{Vxr*9oO  
//保存下载信息(文件指针位置) +dqk 6RE  
private void write_nPos() OZ(Dpx(Q  
{ a$C2}  
try{ Ho|o,XvLv  
output = new DataOutputStream(new FileOutputStream(tmpFile)); hMNJ'i}  
output.writeInt(nStartPos.length); <\ y!3;  
for(int i=0;i<nStartPos.length;i++) k0H?9Z4k5  
{ NFB *1_m  
// output.writeLong(nPos); 6N9 c<JC  
output.writeLong(fileSplitterFetch.nStartPos); n 11LxGwk  
output.writeLong(fileSplitterFetch.nEndPos); E)C.eW /  
} ~'NX~<m  
output.close(); yOX&cZ[  
} %9t{Z1$  
catch(IOException e){e.printStackTrace ();} nAIH`L"X  
catch(Exception e){e.printStackTrace ();} 5JS ZLC  
} xLA~1ZSVJw  
} sf YCz  
)HEfU31IC  
//读取保存的下载信息(文件指针位置) WHp97S'd  
private void read_nPos() TNh=4xQ}  
{ J"diFz+20  
try{ fx<FIj7  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sB?2*S"X)<  
int nCount = input.readInt(); 8$\Za,)g  
nStartPos = new long[nCount]; 6tOCZ'f  
nEndPos = new long[nCount]; ?F ce!J  
for(int i=0;i<nStartPos.length;i++) RTK}mhnV  
{ 9z #P  
nStartPos = input.readLong(); J5O.*&  
nEndPos = input.readLong(); ID)^vwn  
} gh TcB  
input.close(); qv *3A?uzr  
} 24/ /21m  
catch(IOException e){e.printStackTrace ();} XAkK:}h  
catch(Exception e){e.printStackTrace ();} E[S? b=^  
} Iha[G u  
;xfO16fNk  
haCKv   
private void processErrorCode(int nErrorCode) 92ZWU2"  
{ ovo/!YJ2  
System.err.println("Error Code : " + nErrorCode); CK2B  
} y>$1 UwQ  
B1E$v(P3M  
'0Lov]L  
//停止文件下载 nt=x]wEC  
public void siteStop() P^"R4T  
{ M~als3  
bStop = true; H#+\nT2m  
for(int i=0;i<nStartPos.length;i++) jk )Vb  
fileSplitterFetch.splitterStop(); 3S5^ `Ag#  
@|BD|{k  
uG;?vvg>  
} PkTf JQP8  
} [cDbaq,T  
//负责部分文件的抓取 cA<<& C  
**FileSplitterFetch.java H#35@HF*o  
*/ 3 -tO;GKb  
package NetFox; Dv@ PAnk3C  
{-HDkG' 8  
s2^B(wP  
import java.io.*; sm1;MF]/u  
import java.net.*; k=?^){[We  
Jn=42Q:>  
\]I  
public class FileSplitterFetch extends Thread { 8"x9#kyU<3  
(_K_`5d;QI  
)Ob]T{GY  
String sURL; //File URL X'f)7RbT  
long nStartPos; //File Snippet Start Position FqwIJ|ct  
long nEndPos; //File Snippet End Position \ZMP_UU(  
int nThreadID; //Thread's ID C,"=}z1P  
boolean bDownOver = false; //Downing is over bG(x:Py&  
boolean bStop = false; //Stop identical |H W( vA  
FileAccessI fileAccessI = null; //File Access interface +oZH?N4yaM  
b0 &  
+Qs!Nhsq  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C`NmZwL  
{ =p q:m  
this.sURL = sURL; DVh)w}v  
this.nStartPos = nStart; MWs~#ReZ  
this.nEndPos = nEnd; hk_g2g  
nThreadID = id; @ .gPJMA  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F}'wH-qp  
} X'x3esw w  
V.8%|-d  
[/cIUQ  
public void run() hU" F;4p  
{ ($62o&I  
while(nStartPos < nEndPos && !bStop) RDJ+QOVKg  
{ F+uk AT  
\lEkfcc  
2bLI%gg3  
try{ PO o%^'(  
URL url = new URL(sURL); ?v4E<iXs  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .x-J44i@/  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3+(z_!Qh  
String sProperty = "bytes="+nStartPos+"-"; 1k[GuG%/K  
httpConnection.setRequestProperty("RANGE",sProperty); % :/_f  
Utility.log(sProperty); j;\[pg MR/  
l^W uS|G[  
CxDcY  
InputStream input = httpConnection.getInputStream(); s8vKKvs`9  
//logResponseHead(httpConnection); OCNPi4  
Yw)Fbt^  
?3q@f\fZ  
byte[] b = new byte[1024]; n@ [  
int nRead; o=_c2m   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zkexei4^<  
{ yMxTfR  
nStartPos += fileAccessI.write(b,0,nRead); g^l RG3a  
//if(nThreadID == 1) OJ1tV% E  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YQd:M%$  
} ? ?[g}>  
#jA)>z\Q^  
{@.Vh]  
Utility.log("Thread " + nThreadID + " is over!"); ,T|x)"uA`  
bDownOver = true; VagT_D  
//nPos = fileAccessI.write (b,0,nRead); 66\jV6eH7L  
} +Gh7^v|"  
catch(Exception e){e.printStackTrace ();} Y#HI;Y^RP  
} 6B6vP%H#  
} }x:f%Z5h  
gXy -Mpzp  
gU;&$  
//打印回应的头信息 Ck'aHe22'  
public void logResponseHead(HttpURLConnection con) cb$-6ZE/  
{ vFQ,5n;fF  
for(int i=1;;i++) O0hu qF$K  
{ iw\%h9  
String header=con.getHeaderFieldKey(i); LFf`K)q  
if(header!=null) QyGnDomQ  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;Vu5p#,O<M  
Utility.log(header+" : "+con.getHeaderField(header)); RMP9y$~3pU  
else (9C<K<  
break; Kat&U19YH  
} 7L3ik;>  
} F)Oe9x\/  
[6tSYUZs  
%j+xgX/&  
public void splitterStop() )T|L,Lp  
{ %J~WC$=Qv  
bStop = true; p&Ed\aQ%z;  
} _O]xey^r  
:50b8  
p2 %  
} )uheV,ZnY  
}}r> K}  
FN^FvQ  
/* GP a`e  
**FileAccess.java PaWr[ye  
*//文件访问(定位,写) $`J_:H%  
package NetFox; #07!-)Gv  
import java.io.*; t ^SzqB  
eu#'SXSC F  
se9>.}zZN  
public class FileAccessI implements Serializable{ _$s> c!t,#  
IV`%V+ f  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'LSz f/w  
RandomAccessFile oSavedFile; ytAWOt}`  
long nPos; \6!W05[ Q  
A1i!F?X  
(u1m]WYL  
public FileAccessI() throws IOException oBQm05x"  
{ h2Bz F  
this("",0); 3V<&|  
} >I"V],d!6  
)> a B  
5&!c7$K0  
public FileAccessI(String sName,long nPos) throws IOException {XCf-{a]~  
{ 9KuD(EJS  
oSavedFile = new RandomAccessFile(sName,"rw"); G }nO@  
this.nPos = nPos; cr;`Tl~}s  
oSavedFile.seek(nPos); +^|iZbZKx  
}  aSutM  
r'7LR  
S<wj*"|.s  
public synchronized int write(byte[] b,int nStart,int nLen) PoSpkJH  
{ a;AzY'R  
int n = -1; Dt|)=a  
try{ EHf\L  
oSavedFile.write(b,nStart,nLen); `'S0*kMT  
n = nLen; 9 ; i\g=  
} Cb;WZ3HR  
catch(IOException e) %;xOB^H^  
{ ~@W*r5/  
e.printStackTrace (); Kg\R+i@#<  
} K }$&:nao  
3L5r*fa  
U9hS<}<Ki  
return n; OQ&'Dti  
} RP4Ku9hk  
` uCIXb  
{FO$yw=>  
} dt\jGD  
G4 _,  
%3r:s`{  
/* KKe8 ly,  
**SiteInfoBean.java "tk-w{>  
*/ "Zv~QwC  
package NetFox; $A_]:qI2  
%kshQ%P)?  
Q>< 0[EPj3  
public class SiteInfoBean { <.K4JlbT  
9LJZ-/Wq  
YX*x&5]lq  
private String sSiteURL; //Site's URL 8+Llx  
private String sFilePath; //Saved File's Path c3%@Wj:fo  
private String sFileName; //Saved File's Name `{v?6:G:Q  
private int nSplitter; //Count of Splited Downloading File BqK(DH^9N  
!~i' -4]  
Z~  
public SiteInfoBean() 3>M&D20Z  
{//nSplitter的缺省值为5 !U%T&?E l  
//default value of nSplitter is 5  >w6taX  
this("","","",5); fh8j2S9J  
} s"KJiQKGM  
),:c+~@@kT  
~ Heb1tl ;  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R\3VB NX.g  
{ K$ }a8rH  
sSiteURL= sURL; 5Qwh(C^H  
sFilePath = sPath; AM"jX"F9/  
sFileName = sName; ENVk{QE!  
this.nSplitter = nSpiltter; #18FA|   
d~J-|yyT  
O Wp%v_y]  
} B5%n(,Lx  
`mfq 2bVc  
/UcV  
public String getSSiteURL() uP $ Cj  
{ zw<p74DH  
return sSiteURL; . 5y"38e  
} ZzGahtx)Y  
y m,H@~  
)::>q5c  
public void setSSiteURL(String value) 9# 4Y1LS)  
{ #FOqP!p.E  
sSiteURL = value; Cs3^9m6;d  
} )m3Uar  
/wShUR{  
W<ZK,kv  
public String getSFilePath() O)|P,?  
{ AFvgbn8Qh  
return sFilePath; O4 3YY2  
} INs!Ame2  
] Wy)   
Psura$:  
public void setSFilePath(String value) [&[^G25  
{ hY5WJ;  
sFilePath = value; f"u *D,/sS  
} <:>SGSE9  
&GTI  
}TQ{`a@  
public String getSFileName() Am0{8 '  
{ Qhi '') Q  
return sFileName; Y/<lWbj*A  
} '+>fFM,*B  
/ O/`<  
7M_U2cd|TD  
public void setSFileName(String value) gbeghLP[?  
{ /I5X"x  
sFileName = value; :AdDLpk3j  
} n6d9 \  
V"o7jsFH6n  
Jf)bHjC_V  
public int getNSplitter() u=F+(NE"  
{ \6?A!w~6  
return nSplitter; #o/ H~Iv  
} 5Z/GK2[HL  
/M~!sPW&?  
cq&*.  
public void setNSplitter(int nCount) 'TC/vnM  
{ .MW@;  
nSplitter = nCount; &;,,H< p  
} enNiI$H]`_  
} 93qwH%  
`!:q;i]}  
1% F?B-k  
/* r"2V  
**Utility.java 7'-Lp@an  
*/ 9j ]sD/L5q  
package NetFox; HmfG$Z  
X:a`B(@S  
a {}|Bf<  
public class Utility { <}U'V}g  
L9Z;:``p  
RgorkZlVM  
public Utility() ,mS/h~-5n  
{ SVlua@]ChU  
Ok7t@l$  
w~_;yQ  
} o@]So(9f  
o*x*jn:hm  
//线程睡眠 p(xC*KWB  
public static void sleep(int nSecond) XoL JL]+?  
{ 6$a$K,dZ  
try{ $WYbm}j  
Thread.sleep(nSecond); I$NhXZ)KT  
} EV#MQM  
catch(Exception e) tkQH\5  
{ =~Ynz7 /x  
e.printStackTrace (); )#a[-.OI  
} JXG"M#{  
} &zQ2M#{82  
Cz4)Yz  
//日志 `b8v1Os^2  
public static void log(String sMsg) +')f6P;t>=  
{ =cN&A_L(  
System.err.println(sMsg); Y={&5Mir  
} RjF'x  
G$'jEa<:u  
v5;I]?72l~  
public static void log(int sMsg) 9Suu-A  
{ d_n7k g+  
System.err.println(sMsg);  ;N B:e  
} <2!v(EkI  
} >{eCh$L  
g~7Ri-"  
FJ*i\Q/D  
/* ] sz3]"2  
**TestMethod.java Q%/<ZC.Mz6  
*/ ,\ 2a=Fp  
package NetFox; 4!asT;`'  
Q6o(']0  
R1F5-#?'E  
public class TestMethod { {7!UQrm<  
)eUW5 tS  
T5Q{{@Q  
public TestMethod() 'Y$R~e^Y?  
{ ///xx/weblogic60b2_win.exe `c/*H29  
try{ Y+4o B  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8ul&x~2;X  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8<mjh0F-,  
SiteFileFetch fileFetch = new SiteFileFetch(bean); sS&Z ,A  
fileFetch.start(); \;VhYvEH  
} ve ~05mg  
catch(Exception e){e.printStackTrace ();} M3p   
"'g[1Li  
-",=G\XZ  
} *Nyev]8  
`X,yM-(  
rC:?l(8ng3  
public static void main(String[] args) L,d LE-L  
{ TI9UXa:V\  
new TestMethod(); w ;daC(:  
} hYQ_45Z*?  
} *A}cL  
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