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http断点续传简单实现(java)

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/* :)SLi  
**SiteFileFetch.java m\)z& hv<r  
*/ #%rXDGDS  
package NetFox; M8oI8\6[  
import java.io.*; H~^am  
import java.net.*; dd@qk`Zl&A  
7loIX Qw  
%XM wjBM  
public class SiteFileFetch extends Thread { |X,T>{V?y  
s `B"qw  
lED-Jo2  
SiteInfoBean siteInfoBean = null; //文件信息Bean 3M=ym.  
long[] nStartPos; //开始位置 R_e{H^pY^  
long[] nEndPos; //结束位置 zB kS1qMn  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Q-k{Lqa-  
long nFileLength; //文件长度 7y1J69IK  
boolean bFirst = true; //是否第一次取文件 mzLDZ# =b  
boolean bStop = false; //停止标志 I9-vV>:z  
File tmpFile; //文件下载的临时信息 >jD,%yG  
DataOutputStream output; //输出到文件的输出流  |W];8  
o$8v8="p  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) :UGc6  
public SiteFileFetch(SiteInfoBean bean) throws IOException &'uFy0d,  
{ Pwn"!pk  
siteInfoBean = bean; NguJ[  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 0'{0kE[wn  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); /f@VRME  
if(tmpFile.exists ()) nw){}g  
{ l*T> 9yC  
bFirst = false; ;I1}g]  
read_nPos(); ]([:"j  
} 4mq+{c0  
else rLw3\>y  
{ n7>CK?25  
nStartPos = new long[bean.getNSplitter()]; j'Z}; 3y  
nEndPos = new long[bean.getNSplitter()]; eLXG _Qb"  
} U?P5 cN  
 I0trHrX9  
G%_6" s  
+YVnA?r?  
} }J"}5O2,b  
|r[yMI|VR  
2 UU5\ jV6  
public void run() |!NKKvf  
{ L s6P<"V  
//获得文件长度 k7yQEU  
//分割文件 sS/#)/B  
//实例FileSplitterFetch Rd7Xs  
//启动FileSplitterFetch线程 Bt[OGa(q  
//等待子线程返回 &(UVS0=Dp,  
try{ K<'L7>s3lA  
if(bFirst) zA4m !l*eM  
{ Nn5z   
nFileLength = getFileSize(); 28>PmH]7  
if(nFileLength == -1) Ao~ZK[u  
{ Ch8w_Jf1yx  
System.err.println("File Length is not known!"); zY6{ OP!#  
} o-"/1zLg4  
else if(nFileLength == -2) O*^=  
{ WlVp|s{TYP  
System.err.println("File is not access!"); STmn%&  
} I%.KFPV  
else HQlhT  
{ 9t:P1  
for(int i=0;i<nStartPos.length;i++) a=}JW]  
{ S(<r-bV<  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); %upnXRzw  
} EkS7j>:  
for(int i=0;i<nEndPos.length-1;i++) hyqsMkW|  
{ !m)P*Lw  
nEndPos = nStartPos[i+1]; >Q':+|K}  
} SZW+<X  
nEndPos[nEndPos.length-1] = nFileLength; M il ![A1  
} +Gv{Apd"  
} 2gLa4B-  
&(a#I]`9M  
a'=C/ s+  
//启动子线程 ^{\gD23  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 72@lDY4cE  
for(int i=0;i<nStartPos.length;i++) c#X9d8>  
{ SJ$N]<d  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _X5@%/Vz  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9fp@d  
nStartPos,nEndPos,i); LnZzY0  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qd\5S*Z1  
fileSplitterFetch.start(); "e.QiK  
} 8Yfg@"Tn  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l`D^)~o8  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ." 9t<<!  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s *$Re)}S  
nEndPos = " + nFileLength); JRQ{Q"`)  
// fileSplitterFetch[nPos.length-1].start(); z*?-*6W  
<%WN<T{q|  
-=_bXco}  
//等待子线程结束 *PQu9>1w  
//int count = 0; PR rf$& u  
//是否结束while循环 PAG.],"D  
boolean breakWhile = false; b=[gK|fu  
pm$ZKM  
W'2T7ha Es  
while(!bStop) ANB@cK_  
{ LB*qL  
write_nPos(); z~tCag8I(k  
Utility.sleep(500); x;A"S  
breakWhile = true; Exir?G}\  
0].x8{~o  
g%()8QxE1  
for(int i=0;i<nStartPos.length;i++) aRFLh  
{ 01v7_*'R  
if(!fileSplitterFetch.bDownOver) C'8v\C9Ag  
{ ShXk\"  
breakWhile = false; |<nS<x  
break; mEi+Tj zp  
} r(sQI# P  
} ::13$g=T9s  
if(breakWhile) WT(inf[  
break; 'u@_4wWp  
K:PzR,nn  
Xk#"rM< Y  
//count++; [Xp{z tGE  
//if(count>4) yn&AMq ]o  
// siteStop(); =%u\x=u|  
} RQ?T~ASs  
a[TR_ uR  
gucd]VH  
System.err.println("文件下载结束!"); <~aQ_l  
} >r Nff!Ow  
catch(Exception e){e.printStackTrace ();} en\shc{R]`  
} Qd~M;L O"i  
?Y6MC:l<  
+rEqE/QF  
//获得文件长度 >dH5n$Gb  
public long getFileSize() rEI]{?eoF  
{ g=eYl_P6  
int nFileLength = -1; NOOP_:(7H  
try{ :,.g_@wvG  
URL url = new URL(siteInfoBean.getSSiteURL()); M6n9>aW4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KP)BD;  
httpConnection.setRequestProperty("User-Agent","NetFox"); iUuG}rqj  
-$pS {q;  
]W,K}~!   
int responseCode=httpConnection.getResponseCode(); >z0~!!YZ  
if(responseCode>=400) /<Nb/#8  
{ m5K B#\  
processErrorCode(responseCode); ~50b$];y  
return -2; //-2 represent access is error &{B-a  
} oZvQ/|:p!  
d~L`*"/)[  
1_JxDT,=>  
String sHeader; wg6![Uh  
.0x+b-x  
u rGk_.f  
for(int i=1;;i++) wk { 9  
{ q|PB[*T  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QusEWq)}<  
//Utility.log(in.readLine()); xl5n(~g)p  
sHeader=httpConnection.getHeaderFieldKey(i); >`rK=?12<  
if(sHeader!=null) }qUNXE@  
{ 6 bL+q`3>  
if(sHeader.equals("Content-Length")) 7?6?`no~JJ  
{ )k5lA=(Yr+  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /a7tg+:  
break; ,e"A9ik#  
} yQwj [  
} c"aiZ(aP  
else j!r 4p,  
break; Ph&AP*Fq  
} 3[Pa~]yS  
} YxMOr\B  
catch(IOException e){e.printStackTrace ();} ]a% *$TF  
catch(Exception e){e.printStackTrace ();} T!6H5>zA  
f_1#>]  
L2ePWctq}  
Utility.log(nFileLength); !Ju?REH   
2A3;#v  
\Cx) ~bq<  
return nFileLength; <YbOO{  
} $)| l#'r  
W(*:8}m,p  
e_J_rx  
//保存下载信息(文件指针位置) 9kPwUAw  
private void write_nPos() oF/5mh__(K  
{ '< OB  j  
try{ H~-zq} 4  
output = new DataOutputStream(new FileOutputStream(tmpFile)); RVN"lDGA  
output.writeInt(nStartPos.length); %UJ!(_  
for(int i=0;i<nStartPos.length;i++) .vRLK  
{ &J|3uY,'j  
// output.writeLong(nPos); 3j.Ft*SV  
output.writeLong(fileSplitterFetch.nStartPos); ]UnZc  
output.writeLong(fileSplitterFetch.nEndPos); Xu#\CYk  
} gF% lwq  
output.close(); L1u  
} Auhw(b>}TW  
catch(IOException e){e.printStackTrace ();} w<_.T#  
catch(Exception e){e.printStackTrace ();} fys@%PZq  
} qs6yEuh#  
<!:,(V>F(C  
p$}iBk0B(z  
//读取保存的下载信息(文件指针位置) -@ #b<"1  
private void read_nPos() <[xxCW(2  
{ GY4 :9Lub7  
try{ p7(xk6W  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ty%4#9``0  
int nCount = input.readInt(); (]0$^!YK  
nStartPos = new long[nCount]; R!xs;|]  
nEndPos = new long[nCount]; )!MeSWGq  
for(int i=0;i<nStartPos.length;i++) '<f4POy!  
{  TyMR m  
nStartPos = input.readLong(); ?8Cxt|o>  
nEndPos = input.readLong(); )rD] y2^<  
} !@-j!Ub  
input.close(); !B?/6XRUx  
} NFGC.<  
catch(IOException e){e.printStackTrace ();} N s9cx  
catch(Exception e){e.printStackTrace ();} !U#kUj:4I  
} `"[VkQFB/  
aPB %6c=  
o_U=]mEDY  
private void processErrorCode(int nErrorCode) 9;Ezm<VQ  
{ 'DF3|A],  
System.err.println("Error Code : " + nErrorCode); !-r@_tn|  
} s)yEVh  
zsI0Q47\  
T4T_32`XR  
//停止文件下载 '9GHmtdO,  
public void siteStop() kgK7 T  
{ AW6]S*rh  
bStop = true; v:CYf_  
for(int i=0;i<nStartPos.length;i++) YP~d1BWvf  
fileSplitterFetch.splitterStop(); -$;H_B+.  
C 0*k@kGy  
6KhHS@Z  
} 8E/$nRfO d  
} J),7ukLu^  
//负责部分文件的抓取 c[<lr  
**FileSplitterFetch.java [w~teX0!  
*/ N;D (_:^  
package NetFox; OM]p"Jd  
{AIP\  
<(d ^2-0  
import java.io.*; 1*?IDYB  
import java.net.*; N!;Y;<Ro_  
E?z 3&C  
FqsG#6|x  
public class FileSplitterFetch extends Thread { i>T{s-3v  
/'E+(Y&:J  
$$ {ebt  
String sURL; //File URL c@ En4[a'  
long nStartPos; //File Snippet Start Position * ok89 ad  
long nEndPos; //File Snippet End Position ] V]~I.  
int nThreadID; //Thread's ID 6\O4R  
boolean bDownOver = false; //Downing is over -O~WHi5}  
boolean bStop = false; //Stop identical |IH-a"  
FileAccessI fileAccessI = null; //File Access interface 0"u*Kn  
qChS} Q  
J~ v<Z/gm  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]G&?e9OA  
{ jb)z[!FbM  
this.sURL = sURL; P>L-,R(7e  
this.nStartPos = nStart; OdRXNk:k-j  
this.nEndPos = nEnd; 9|jIrS%/~  
nThreadID = id; _w+sx5  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 rf;R"Uc  
} VjYfnvE  
30FYq?  
RNoS7[&  
public void run() ,k{{ZP P  
{ \I#lLP  
while(nStartPos < nEndPos && !bStop) UN| "D]>/  
{ ]ZO^@sH  
\R&`bAdk  
K]@6&H-b|  
try{ 2|EH Ny!  
URL url = new URL(sURL); BAm H2"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6$SsdT|8B  
httpConnection.setRequestProperty("User-Agent","NetFox"); D8`,PXtV  
String sProperty = "bytes="+nStartPos+"-"; '4HwS$mW3  
httpConnection.setRequestProperty("RANGE",sProperty); U@D=.6\B  
Utility.log(sProperty); }'kk}2ej`  
]|Vm!Q  
L4.yrA-]C%  
InputStream input = httpConnection.getInputStream(); bvEk.~tC'  
//logResponseHead(httpConnection); *KxV;H8/  
Jd1eOeS  
D6bCC; h=  
byte[] b = new byte[1024]; 'ycs{}'  
int nRead; `{F8#    
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ),bdj+wr78  
{ ^fnRzX  
nStartPos += fileAccessI.write(b,0,nRead); uHz D  
//if(nThreadID == 1) X /5tZ@  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); , X$S4>  
} M/d!&Bk  
9]NsWd^^  
xZ`t~4qR  
Utility.log("Thread " + nThreadID + " is over!"); 'r1&zw(  
bDownOver = true; |V!A!tB  
//nPos = fileAccessI.write (b,0,nRead); ,dBtj8=  
} b^Rg_,s  
catch(Exception e){e.printStackTrace ();} !6<2JNf  
} ^N Et{]x  
} ]o,)#/' $  
aM?7'8/  
'-w G  
//打印回应的头信息 J_rCo4}  
public void logResponseHead(HttpURLConnection con) EF)kYz!@  
{ c~R ElL  
for(int i=1;;i++) \FVR'A1  
{ =\X<UA}  
String header=con.getHeaderFieldKey(i); oH6(Lq'q  
if(header!=null) n6Q 3X  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cY\-e?`=4  
Utility.log(header+" : "+con.getHeaderField(header)); [`ttNW(_  
else ,Hys9I  
break; Qg9{<0{u  
} ~Gwn||g78  
} gvA&F |4  
Htsa<t F  
(CZRX9TT1  
public void splitterStop() lzS"NHs<g(  
{ kf"cd 1  
bStop = true; Vx* =  
}  r) X?H  
%5F=!( w  
*WX6C("M  
} b;soMilz  
wy) Frg  
%HYC-TF#  
/* I &{dan2  
**FileAccess.java ZP%^.wxC  
*//文件访问(定位,写) 5^* d4[&+  
package NetFox; [&+wW  
import java.io.*; @ULr)&9  
aN;L5;m#>{  
ZV;#ZXch  
public class FileAccessI implements Serializable{ 'Iu$4xo`[  
xO?~@5  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cE]tvL:g  
RandomAccessFile oSavedFile; zI7-xqZ  
long nPos; 1/le%}mK  
mi97$Cr2  
(x.K%QC)  
public FileAccessI() throws IOException  KsUsj3J  
{ %j^=  
this("",0); Atfon&^  
} GVEjB;  
I[[rVts  
"me J n/  
public FileAccessI(String sName,long nPos) throws IOException GueqpEd2  
{ I"@5=m5  
oSavedFile = new RandomAccessFile(sName,"rw"); KY|Q#i|pM  
this.nPos = nPos; [xI@)5Xk  
oSavedFile.seek(nPos); Y/@4|9!  
} _v2FXm   
^vG*8,^S=8  
8swj'SjX  
public synchronized int write(byte[] b,int nStart,int nLen) 2^ UFP+Yw  
{ ]^Q`CiKd  
int n = -1; x5PQ9Bw,  
try{ "F%cn@l  
oSavedFile.write(b,nStart,nLen); vRT1tOQ$  
n = nLen; %X[|7D-  
} _Dk;U*2  
catch(IOException e) zD)2af  
{ b,318R8+G  
e.printStackTrace (); n$b/@hp$z  
} m! p'nP  
|(S=G'AtU  
CiPD+I  
return n; c>DAR  
} PJ #uYM  
u.!Pda  
-} Z  
} t5eux&C  
IOIGLtB  
@ @# G.  
/* 8Cm^#S,+  
**SiteInfoBean.java {W0]0_mI(  
*/ % ;6e@U}  
package NetFox; C=hE@  
tb@/E  
\>I&UFfH)4  
public class SiteInfoBean { )cOm\^,  
 "&C'K  
4H1s"mP<  
private String sSiteURL; //Site's URL b(~NqV!i  
private String sFilePath; //Saved File's Path 6Ajiz_~U  
private String sFileName; //Saved File's Name OkFq>;{a  
private int nSplitter; //Count of Splited Downloading File pV>/ "K  
U<#i\4W  
DQ'+,bxk=9  
public SiteInfoBean() vx-u+/\  
{//nSplitter的缺省值为5 P5aHLNit  
//default value of nSplitter is 5 <ygkK5#q  
this("","","",5); k ( R  
} -M[5K/[  
k`TEA?RfQ  
y l3iU:+V  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PU-;Q@< E  
{ U15Hq*8Z  
sSiteURL= sURL; yY,.GzIjCj  
sFilePath = sPath; YjG0: 9  
sFileName = sName; l<qxr.X  
this.nSplitter = nSpiltter; ]p#Zdm1EL  
KN+*_L-  
nTYqZlI,  
} }-8K*A3  
XPX{c|]>.  
q:nYUW o   
public String getSSiteURL() ]vu' +F$  
{ ;%U`lE0  
return sSiteURL; 1>|p1YZ"  
} 8vaqj/  
MK=:L   
v3@)q0@  
public void setSSiteURL(String value) >#>YoA@S  
{ wmT3 >  
sSiteURL = value; BJlF@F#  
} 9 -TFyZYU  
+%>L;'L ^X  
q .?D{[2  
public String getSFilePath() LY^BkH'  
{ , :kCt=4%  
return sFilePath; "w_(p|cm=  
} TJO|{Lxm  
Gzm[4|nO^  
v_G4:tY  
public void setSFilePath(String value) gw5CU)r4$  
{ S9xC> |<  
sFilePath = value; =#>P !  
} qLPI^g,  
} 10Dvt>+  
wePMBL1P*  
public String getSFileName() w|$;$a7)  
{ +  ^~n09  
return sFileName; iAXx`>}m  
} DpTQPu9  
TmUn/  
-98bX]8  
public void setSFileName(String value) Y3-15:-  
{ o]k[l ;  
sFileName = value; -4HI9Czts  
} (r7~ccy4  
cLB"<mG  
$x`U)pv  
public int getNSplitter() XvdK;  
{ \W$>EH  
return nSplitter; qP]Gl--q{  
} ozGK -$  
VT0I1KQx.  
tM !1oWH  
public void setNSplitter(int nCount) OO\UF6MCU  
{ 6%fU}si,  
nSplitter = nCount; az19-QIcg  
} c{&sf y  
} 9$Hgh7'hvs  
ql_aDo j  
`Y+p7*Qr2  
/* EcP"GO5  
**Utility.java eQYW>z'%,  
*/ XFM6.ye  
package NetFox; /j.V0%  
C0kwI*)  
cIq3En  
public class Utility { =P2T&Gb  
>r{,$)H0  
1_<'S34  
public Utility() cL`l1:j\}  
{ N-vr_4{g  
#>!!#e!*  
EV~_-YC   
} 6Lz&"C,`  
Le_?x  
//线程睡眠 n1!u aUC  
public static void sleep(int nSecond) Yz{UP)TC  
{ R=PjLH&)  
try{ i%-c/ lop  
Thread.sleep(nSecond); AMtFOXx%I  
} 33 N5>}  
catch(Exception e) TNiF l hq  
{ F1 MPo;e  
e.printStackTrace ();  BeP0lZ  
} !f"@pR6  
} o<%Sr*  
R#Ss_y  
//日志 F5E KWP  
public static void log(String sMsg) b/2t@VlL  
{ _D z4 }:9  
System.err.println(sMsg); ~Uga=&  
} v bh\uv&  
/A{znE  
bC"#.e  
public static void log(int sMsg) u QCQ$  
{ ;:' A{&0N  
System.err.println(sMsg); PBkKn3P3  
} 5w{_WR6,  
} Jd)|== yD  
Z=wLNmH  
6B|IbQ^  
/* t0hg!_$bq  
**TestMethod.java "y5c)l(Rg  
*/ MbjH\XRB  
package NetFox; x+^iEj`gk  
/SP^fB*y  
B;_M52-B  
public class TestMethod { .K:>`~<)  
et)A$'Q  
8Gs{Zfp!D  
public TestMethod() K{"(|~=U  
{ ///xx/weblogic60b2_win.exe Rz%+E0  
try{ 'N'EC`R  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z?1.Y7Npr  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Qs</.PO  
SiteFileFetch fileFetch = new SiteFileFetch(bean); C3WqUf<8`{  
fileFetch.start(); V"\t  
} IDwneFO  
catch(Exception e){e.printStackTrace ();} QiB:K Pz[  
Z\`uI+`  
6(X(f;MEl  
} %'@&j2j>  
QBDi;Xzb+  
Q<Utwk?nL  
public static void main(String[] args) 5f}wQ  
{ !=eui$]  
new TestMethod();  ;-U :t4  
} +*F ;l\R  
} FRX'"gIR0  
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