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http断点续传简单实现(java)

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/* h&m4"HBL_  
**SiteFileFetch.java #EX NSr  
*/ yU< "tgE  
package NetFox; &=hkB9 ;  
import java.io.*; 7xjihl3  
import java.net.*; n% ={!WD  
fIm=^}?fwK  
W3-g]#\?  
public class SiteFileFetch extends Thread { }-15^2  
JzuP A I  
5r(Y,m"?  
SiteInfoBean siteInfoBean = null; //文件信息Bean &L4>w.b"N  
long[] nStartPos; //开始位置 H4JwgQ  
long[] nEndPos; //结束位置 yDXW#q  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 pJPP6Be<  
long nFileLength; //文件长度 W,sPg\G 3  
boolean bFirst = true; //是否第一次取文件 UWg+7RL  
boolean bStop = false; //停止标志 l. 0|>gj`0  
File tmpFile; //文件下载的临时信息 x]<0Kq9K  
DataOutputStream output; //输出到文件的输出流 L<H6AzR+  
EGJrnz8  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 1\ab3n  
public SiteFileFetch(SiteInfoBean bean) throws IOException H"J>wIuGX  
{ XZ[3v9?&n  
siteInfoBean = bean; -q}I; cH  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); :dj=kuUTbu  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); gtw?u b  
if(tmpFile.exists ()) gaxxB]8  
{ &<oDl _^  
bFirst = false; #i0f}&  
read_nPos(); QsH?qI&2jp  
} eCXw8  
else :}p<Hq 8Z  
{ 8I,/ysT:  
nStartPos = new long[bean.getNSplitter()]; X UcM~U-  
nEndPos = new long[bean.getNSplitter()]; j`ybzG^  
} tboc7Hor4  
=y WHm  
f`"@7-N  
p-,(P+Np  
} 8$y5) ~Q  
7Hzv-s  
7=[/J*-m  
public void run() R?H[{A X  
{ k#pNk7;MZ  
//获得文件长度 71!'k>]h  
//分割文件 7) 37AKw  
//实例FileSplitterFetch S7 WT`2  
//启动FileSplitterFetch线程 ,G!mO,DX  
//等待子线程返回 u<K{=94!e  
try{ h\PybSW4s  
if(bFirst) Xhm)K3RA*T  
{ RoeLf Ow  
nFileLength = getFileSize(); e{7"7wn=  
if(nFileLength == -1) ( t59SY  
{ mVdg0  
System.err.println("File Length is not known!"); B{\qYL/~  
} gWpG-RL0  
else if(nFileLength == -2)  T6N~L~J  
{ `CF.-Vl3J#  
System.err.println("File is not access!"); ;;lOu~-*$p  
} %hH@< <b(s  
else $V2.@ X  
{ h;S?  
for(int i=0;i<nStartPos.length;i++) l fJ lXD  
{ BhCOT+i;c  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Y[Kpd[)[v  
} 8$C?j\J|*  
for(int i=0;i<nEndPos.length-1;i++) mv\S1[<T  
{ 9  7Mi{Zz  
nEndPos = nStartPos[i+1]; 1JWo~E'  
} 9 `z^'k&  
nEndPos[nEndPos.length-1] = nFileLength; & 24$*Oe  
}  D/]  
} )ME'qA3K  
2!;U.+(  
Ki(  
//启动子线程 l"app]uVZ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SQJ }$#=  
for(int i=0;i<nStartPos.length;i++) U<jAZU[L  
{ Gf y9?sa  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c},wW@SF2W  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6 P U]I+  
nStartPos,nEndPos,i); ^F4h:  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bA8RoC  
fileSplitterFetch.start(); JPGEE1!B{b  
} 1_0\_|  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kH}HFl  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :to1%6  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w!~85""  
nEndPos = " + nFileLength); DZ5QC aA  
// fileSplitterFetch[nPos.length-1].start(); L|N[.V9  
q$BS@   
^U[yk'!Y  
//等待子线程结束 ~fR-cXj"  
//int count = 0; UhVJ !NrT  
//是否结束while循环 Xw |6 #^  
boolean breakWhile = false; * J|]E(  
aYd`E4S+  
YCnKX<Wv  
while(!bStop) bo04y)Iz  
{ XYdr~/[HPy  
write_nPos(); 9 Z79  
Utility.sleep(500); do&0m[x%  
breakWhile = true; _5&LV2  
*Ph@XkhU  
UcxMA%Pw7$  
for(int i=0;i<nStartPos.length;i++) >nOzz0,  
{ hR(p{$-T  
if(!fileSplitterFetch.bDownOver) | +r5D4]e  
{ :1,xse  
breakWhile = false; AAPfU_: ^  
break; 2"C,u V@F!  
} I4%25=0?  
} ]#t5e>o|  
if(breakWhile) p4M7BK:nf  
break; 0D:eP``  
L qdz qq  
WuUT>om H  
//count++; hsZ}FLStJ  
//if(count>4) qS}pv  
// siteStop(); )3A%Un#B  
} 6Z7J<0  
Z&j?@k,k  
|VE *_ G  
System.err.println("文件下载结束!"); ^dCSk==  
} m0_B[dw  
catch(Exception e){e.printStackTrace ();} 3P[u>xE  
} cu#s}* Ip  
$G@^!(  
71inHg  
//获得文件长度 "R9^X3;  
public long getFileSize() @(_f}S gfE  
{ tDwj~{a~  
int nFileLength = -1; A.@Af+  
try{ >S=,ype~G  
URL url = new URL(siteInfoBean.getSSiteURL()); 9d1 G u"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7UA|G2Zr  
httpConnection.setRequestProperty("User-Agent","NetFox"); j3yz"-53e  
ZK8I f?SD  
Cv;\cI"&  
int responseCode=httpConnection.getResponseCode(); ga+Z6|t  
if(responseCode>=400) w\2yippI  
{ qk=0ovUzg  
processErrorCode(responseCode); 6kM'f}t[C  
return -2; //-2 represent access is error ;gmfWHB<  
} Y%A KN  
g"o),$tm  
95X!{\  
String sHeader; k=8LhO  
~sUWXw7~  
T_1p1Sg  
for(int i=1;;i++) gg}^@h&?  
{ Z5%TpAu[  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r(uf yC&  
//Utility.log(in.readLine()); e lzKtVw  
sHeader=httpConnection.getHeaderFieldKey(i); 2-!n+#Cdf  
if(sHeader!=null) 2B=''W  
{ <rAk"R^  
if(sHeader.equals("Content-Length")) jFThW N  
{ iz pFl@WS  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .?CumaU  
break; ps=+wg?]  
} 6h_OxO&!U  
} \QKr2|  
else kx_PMpc  
break; i1JWdHt  
} |nTZ/MXbw  
} Y\1XKAfB  
catch(IOException e){e.printStackTrace ();} ` "JslpN  
catch(Exception e){e.printStackTrace ();} V- HO_GDo  
[osm\w49  
'-k~qQk)6  
Utility.log(nFileLength); ?B`Yq\L)  
*N|s+  
y/}ENUGR  
return nFileLength; {pof=G  
} y$^.HI02jP  
OP}8u"\Z  
*S$`/X  
//保存下载信息(文件指针位置) ;UB$Uqs6  
private void write_nPos() }4M4D/=  
{ C;_*vi2u  
try{ )ls<"WTC.  
output = new DataOutputStream(new FileOutputStream(tmpFile)); )TFBb\f>v  
output.writeInt(nStartPos.length); A7X-),D  
for(int i=0;i<nStartPos.length;i++) |~I-  
{ A}cGag+sp  
// output.writeLong(nPos); {f }4l  
output.writeLong(fileSplitterFetch.nStartPos); Ap [}[:U  
output.writeLong(fileSplitterFetch.nEndPos); qmJ^@dxs  
} 5{uK;Vxse  
output.close(); F9&ae*>,  
} ={a_?l%  
catch(IOException e){e.printStackTrace ();} Fkvf[!Ci  
catch(Exception e){e.printStackTrace ();} dzbFUDJ  
} af>^<q  
nb30<h  
0en Bq>vr  
//读取保存的下载信息(文件指针位置) _xmS$z)TO  
private void read_nPos() i-YSt5iq  
{ :Z R5<Y>  
try{ pba`FC4R  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J$D/-*/@  
int nCount = input.readInt(); _O$7*k  
nStartPos = new long[nCount]; Puq  
nEndPos = new long[nCount]; )azK&f@tR|  
for(int i=0;i<nStartPos.length;i++) W<c95QD.  
{ |?gO@?KDZ  
nStartPos = input.readLong(); N<N uBtkA  
nEndPos = input.readLong(); NI^jQS M]  
} my}l?S[2d@  
input.close(); t_"]n*zk1  
} &y+)xe:&S  
catch(IOException e){e.printStackTrace ();} r.ib"W#4  
catch(Exception e){e.printStackTrace ();} U)Jwo O  
} H/^t]bg,  
sK/Z 'h{|  
@Rw]boC  
private void processErrorCode(int nErrorCode) yEPkF0?  
{ t%fcp  
System.err.println("Error Code : " + nErrorCode); (7*((  
} B.#.gB#C  
eJy}W /  
>4G~01  
//停止文件下载 Q3'L\_1L  
public void siteStop() <HfmNhI85(  
{ <-(n48  
bStop = true; \sEH)$R'  
for(int i=0;i<nStartPos.length;i++) >mW*K _~  
fileSplitterFetch.splitterStop(); e6i m_ Tk  
s= bP@[Gj  
o:c:hSV  
} MC~<jJ,  
} \"| 7o8  
//负责部分文件的抓取 vUR@P  -  
**FileSplitterFetch.java 3Hi[Y[O`%P  
*/ oIv\Xdc81  
package NetFox; z5 g4+y,  
N Wf IRL  
RQ;}+S  
import java.io.*; gkFw=Cd  
import java.net.*; 3y}8|ML  
D16w!Mnz{K  
2I>`{#fV  
public class FileSplitterFetch extends Thread { r:U/a=V  
MWI7u7{  
_-:CU  
String sURL; //File URL .!)i    
long nStartPos; //File Snippet Start Position a^7HI,  
long nEndPos; //File Snippet End Position ZkmY pi[  
int nThreadID; //Thread's ID *q*$%H  
boolean bDownOver = false; //Downing is over eE5j6`5i  
boolean bStop = false; //Stop identical h1+y.4  
FileAccessI fileAccessI = null; //File Access interface NRMEZ\*L  
+GL[uxe "  
Ya29t 98Pk  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Jy P$'v~  
{ >c=-uI  
this.sURL = sURL; D zdKBJT+  
this.nStartPos = nStart; K)#6&\0tT  
this.nEndPos = nEnd; ld[BiP`B2V  
nThreadID = id; "Ky&x$dje  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |lMc6C  
} B4eV$~<  
S#b)RpY  
NJmyp!8  
public void run() >^GAfvW  
{ "V <WC"  
while(nStartPos < nEndPos && !bStop)  NArr2o2  
{ xp F(de  
v!j%<H`NI  
eL1)_M;{  
try{ P*/ig0_fM  
URL url = new URL(sURL); 9;ie[sU:u  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fbW<c`LH  
httpConnection.setRequestProperty("User-Agent","NetFox"); 30b dcDm,  
String sProperty = "bytes="+nStartPos+"-"; l9z{pZ\KM  
httpConnection.setRequestProperty("RANGE",sProperty); [8'^"  
Utility.log(sProperty); NL-V",gI-~  
Y'Yu1mH)  
ttY[\D&ZS  
InputStream input = httpConnection.getInputStream(); &HtG&RvQf  
//logResponseHead(httpConnection); *YP:-  
8 Y))/]R  
|4!G@-2V:I  
byte[] b = new byte[1024]; ltlnXjRUv  
int nRead; OWZ;X}x  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .RpWE.C  
{ w"q^8"j!  
nStartPos += fileAccessI.write(b,0,nRead); :_:o%  
//if(nThreadID == 1) " ""pe+Y  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KvumU>c#A  
} P=m l;xp  
9)$gD  
H`nd |  
Utility.log("Thread " + nThreadID + " is over!"); *})Np0k  
bDownOver = true; !X\aZ{}Q  
//nPos = fileAccessI.write (b,0,nRead); d Z x  
} ->'xjD  
catch(Exception e){e.printStackTrace ();} '[p0+5*x  
} /Zg4JQ~  
} ,VZ<r5NT  
+&[X7r<  
w g^'oy  
//打印回应的头信息 = ,c!V  
public void logResponseHead(HttpURLConnection con) -/R?D1kOq  
{ "DSRyD0M  
for(int i=1;;i++) 9P*p{O{_  
{ 1"No~/_  
String header=con.getHeaderFieldKey(i); $9ys! <g  
if(header!=null) H^JFPvEc  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KeWIC,kq  
Utility.log(header+" : "+con.getHeaderField(header)); ,p V3O`z  
else I^m9(L4%  
break; I\f\k>;  
} y'_2|5!Qs  
} 0Vj!'=Ntv  
p:xVi0  
r85j /YK  
public void splitterStop() .xe+cK  
{ %UB+N8x`a  
bStop = true; +TN*6V{D  
} X<d`!,bn@  
<tv"I-2  
\J6&Z13Q  
} )D" 2Q:  
@;Xa&*   
cG!dMab(  
/* c3N,P<#  
**FileAccess.java ~8EzK_c  
*//文件访问(定位,写) o)M<^b3KO  
package NetFox; Wb;D9Z  
import java.io.*; =QhK|C!$A  
MS& 'Nj  
c3J12+~;  
public class FileAccessI implements Serializable{ <%m$ V5h  
Z L'krV  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Rw|P$dbu  
RandomAccessFile oSavedFile; +0M0g_sk  
long nPos; S6{u(= H  
Dyh|F\T  
cG5u$B  
public FileAccessI() throws IOException Hu"TEhW(2  
{ Ub`vf4EB  
this("",0); w~>tpkUB  
} V L;<+C~  
%18%T{|$e  
Z<`:xFy(  
public FileAccessI(String sName,long nPos) throws IOException cQq78Lo  
{ #NWS)^&1b  
oSavedFile = new RandomAccessFile(sName,"rw"); qsdgG1<  
this.nPos = nPos; a7"Aq:IjU  
oSavedFile.seek(nPos); bf6:J `5Z  
} ?L6pB]l8b  
< mp_[-c  
v8>bR|n5  
public synchronized int write(byte[] b,int nStart,int nLen) 0?=a$0_C  
{ U<wM#l P|Z  
int n = -1; Sw`+4 4  
try{ ;Mz7emt  
oSavedFile.write(b,nStart,nLen); \`-a'u=S  
n = nLen; 40%<E  
} c.}#.-b8  
catch(IOException e) z7R2viR[  
{ "X\6tl7a|  
e.printStackTrace (); H4uHCkj  
} fy={  
7,FhKTV1/  
5?|yYQM0tK  
return n; hx8.  
} !CR#Fyt+9  
&[kFl\  
%wN*Hu~E  
} 5-POY ug  
C'a#.LM  
lbMok/a2o  
/* iIc/%< ;  
**SiteInfoBean.java %nyZ=&u  
*/ u|75r%p>  
package NetFox; t"X^|!hKIF  
[!U! Z'i  
0 D&-BAzi  
public class SiteInfoBean { b ; U  
J6Nhpzp  
&[_D'jm+S0  
private String sSiteURL; //Site's URL U|+ c&TY  
private String sFilePath; //Saved File's Path 64t:  
private String sFileName; //Saved File's Name fiW2m=h_  
private int nSplitter; //Count of Splited Downloading File 6/&|)gW',  
!G;|~|fMV  
r+,JM L   
public SiteInfoBean() t_ id/  
{//nSplitter的缺省值为5 d?N[bA  
//default value of nSplitter is 5 !nTI(--  
this("","","",5); vo^2k13  
} K?*p|&Fi?8  
g:Ry.=F7W  
h=dFSK?*D  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?s[!JeUA  
{ rbI 7 3'  
sSiteURL= sURL; 83_vo0@<6  
sFilePath = sPath; C9n*?Mk:  
sFileName = sName; TsY nsLQY  
this.nSplitter = nSpiltter; |J:m{  
r)oR `\7  
 BF /4  
} -V=,x3Zew  
X- `PF  
+7r?vo1  
public String getSSiteURL() afd.v$63  
{ Qb'Q4@.  
return sSiteURL; -lb%X 3`  
} H6<3'P  
u^( s0q  
WP !u3\91  
public void setSSiteURL(String value) Bs^p!4=  
{ ICzcV };$  
sSiteURL = value; UVgDm&FF  
} S0?e/VWy  
\ \gAa-}:  
-d^c!Iu|  
public String getSFilePath() p$a+?5'Q  
{ >f(M5v(D\  
return sFilePath; q>[}JtXK  
} (Ji=fh+  
SyI i*dH  
Nh1, w  
public void setSFilePath(String value) *kt%.wPJ  
{ fr8hT(,s)  
sFilePath = value; Tfw5i,{  
} cQ(,M  
.cB>ab&  
Cw h[R  
public String getSFileName() scZ&}Ni  
{ <%S[6*6U  
return sFileName; o^Qy71Uj  
} fkD-mRKw  
';I(#J6  
CIAKXYM  
public void setSFileName(String value) +{WZpP},v  
{ jm,:jkr  
sFileName = value; :b<<  
} 0iVeM!bM  
}[]1`2qD  
&;%, Axc  
public int getNSplitter() n\u3$nGL1`  
{ ~{q; - &  
return nSplitter; i7\MVI 8  
} ;TboS-Y  
56H~MnX  
oWBjPsQ  
public void setNSplitter(int nCount) 0r]-Ltvl?}  
{ na3lbwq  
nSplitter = nCount; Ie4X k  
} bDnT><eH  
} 4v.i!U# {  
,$"T/yYer  
&"clBR Vg  
/* ai;-_M+$  
**Utility.java 7A{,)Y/w ^  
*/ p)s *Cw  
package NetFox; DS0:^TLI  
9a]h;r8,9z  
O[z-K K<  
public class Utility { 3#Xv))w1  
#xt-65^  
ltOsl-OpR  
public Utility() *yN#q>1  
{ D9\ EkX  
}a!c  
8jz7t:0  
} /<CgSW}  
lLN5***47J  
//线程睡眠 [y(<1]i-a  
public static void sleep(int nSecond) T)MZ`dM  
{ ab>>W!r@!  
try{ LNF|mS\+D  
Thread.sleep(nSecond); {emym$we  
} o= &/ ;X  
catch(Exception e) iy [W:<c7j  
{ z W*Z  
e.printStackTrace (); ,b74 m  
} (4C_Ft*~j  
} ,9~qLQ0O  
8!qzG4F/  
//日志 !uAqY\Is  
public static void log(String sMsg) {r_x\VC=p  
{ :Kk+wp}f #  
System.err.println(sMsg); $pj;CoPm  
} eV(   
4*?i!<N9  
a4Y43n  
public static void log(int sMsg) Og2G0sWRf  
{ d+%Rg\ v  
System.err.println(sMsg); SlD7 \X&~  
} 4Vv$bbu+  
} T:S[[#f{5  
Ummoph7_@  
iV.j!H7o  
/* @}hdMVi  
**TestMethod.java I?KGb:]|  
*/ Q,n Xc  
package NetFox; +]0/:\(B  
1a'0cSH  
2I0Zr;\f  
public class TestMethod { @c;:D`\p1C  
@H8CU!J  
cR!Mn$m  
public TestMethod() %D E_kwL  
{ ///xx/weblogic60b2_win.exe A8j$c~  
try{ @^,9O92l  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jGtu>|Gj  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 73kI%nNB  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5]Y?NN,GR  
fileFetch.start(); ; e)vk|  
} hGj`IAW  
catch(Exception e){e.printStackTrace ();} z;PF% F  
T;{"lp.  
G>S3?jGk  
} nOq`Cwh9  
PbY=?>0z  
\Z$MH`_nu  
public static void main(String[] args) NkYC(;g  
{ 2 t:CK  
new TestMethod(); aThvq%;  
} H*h4D+Kxv  
} AzFS6<_  
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