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http断点续传简单实现(java)

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/* NTV@,  
**SiteFileFetch.java 8, " 5z_  
*/ n?mV(?N  
package NetFox; 9f #6Q*/  
import java.io.*; 4Ai#$SHLm  
import java.net.*; >Q#\X=a>  
zvOSQxGQ  
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public class SiteFileFetch extends Thread { ~O8Xj6  
b wqd` C  
sjj,q?  
SiteInfoBean siteInfoBean = null; //文件信息Bean s;W1YN  
long[] nStartPos; //开始位置 L %20tm  
long[] nEndPos; //结束位置 UPcx xtC  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 8~|tl,  
long nFileLength; //文件长度 'U*Kb  
boolean bFirst = true; //是否第一次取文件 $s<bKju  
boolean bStop = false; //停止标志 AGMrBd|J{  
File tmpFile; //文件下载的临时信息 .azA1@V|  
DataOutputStream output; //输出到文件的输出流  WfH4*e  
hQ_g OI  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) m {?uR.O  
public SiteFileFetch(SiteInfoBean bean) throws IOException !SAR/sdXf  
{ St|B9V?eEB  
siteInfoBean = bean; ? t_$C,A+  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); P$i d?  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); w,VUWja  
if(tmpFile.exists ()) =bh.V@*  
{ +Z/aB*aVa^  
bFirst = false; iM_Zn!|@\  
read_nPos(); PzH#tG&.j  
} mvXIh";  
else t|]2\6acuc  
{ D<J, 3(Yu  
nStartPos = new long[bean.getNSplitter()]; $.KD nl^  
nEndPos = new long[bean.getNSplitter()]; tdi^e;:?  
} n-x%<j(Xf  
7-j=he/  
v%8S:3  
ZIp"X  
} bCmlSu  
q~6((pWi|  
:\69N/uw`  
public void run() rvETt  
{ ?bw1zYP  
//获得文件长度 J_N`D+m  
//分割文件 `3'4_@7s9  
//实例FileSplitterFetch U}:e-  
//启动FileSplitterFetch线程 Bs;.oK5!n@  
//等待子线程返回 hZ~ \Z S7  
try{ !9g >/9h  
if(bFirst) j6#RV@ p`  
{ hM[QR'\QS  
nFileLength = getFileSize(); $;As7MI  
if(nFileLength == -1) 9#)&  
{ 7thB1cOJ  
System.err.println("File Length is not known!"); 2[~|6 @n  
} M D,+>kh  
else if(nFileLength == -2) R}0xWPt9G  
{ w6G<&1iH  
System.err.println("File is not access!"); |YWX.-aeo  
} =x-@-\m  
else M2rgB%W)m  
{ eGk`Z>  
for(int i=0;i<nStartPos.length;i++) >Ni<itze$i  
{ &vV_,$  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); "2>_eZ#b  
} MB!$s_~o#L  
for(int i=0;i<nEndPos.length-1;i++) 5o2|QL  
{ ,%U'>F?  
nEndPos = nStartPos[i+1]; .?LP$O=  
} Xw]L'+V=  
nEndPos[nEndPos.length-1] = nFileLength; 1zWEK]2.R  
} We:b1sZR  
} -=VGXd  
I1fUV72  
BjAmM*k  
//启动子线程 U`)o$4Bq  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; KpSho<  
for(int i=0;i<nStartPos.length;i++) ]x^v;r~  
{ 6+ C7vG`  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~spfQV~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [fl^1!3{  
nStartPos,nEndPos,i); xSL%1>MrN  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lbnH|;`$]m  
fileSplitterFetch.start(); &'A8R;b}-?  
} +X4/l"|  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m6YDyQC  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5/C#*%EH'  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oa:30@HSb  
nEndPos = " + nFileLength); 2Pic4Z  
// fileSplitterFetch[nPos.length-1].start(); Mhiz{Td  
~-zch=+u  
V^E.9fs,  
//等待子线程结束 *WK0dn  
//int count = 0; pipqXe  
//是否结束while循环 $|n#L6k  
boolean breakWhile = false; 3%DDN\q\u  
" twq#Alx  
+"F9yb  
while(!bStop) ~"8)9&  
{ A-5'OI  
write_nPos(); * v W#XDx  
Utility.sleep(500); yp\s Jc`  
breakWhile = true; CI~ll=9`  
L6f$ID:  
.wJv_  
for(int i=0;i<nStartPos.length;i++) hkoCbR0}8  
{ Z hYOz  
if(!fileSplitterFetch.bDownOver) yVl?gGgh  
{ ;.|).y1/`  
breakWhile = false; }.74w0~0^  
break; FCPi U3  
} (|_N2R!  
} 2#t35fU  
if(breakWhile) w//L2.  
break; 1k?k{Ri  
tC4 7P[b  
C">w3#M%  
//count++; a[A9(Ftn  
//if(count>4) EH~XN9b  
// siteStop(); HL34pmc  
} I'>r  
 g1B[RSWv  
'/ v@q]!  
System.err.println("文件下载结束!"); V]qv,>  
} kSq1Q#Bxq  
catch(Exception e){e.printStackTrace ();} Sz#dld Mz  
} U6 $)e.FO  
U3 y-cgE  
^L +@oS  
//获得文件长度 y;1l].L  
public long getFileSize() 8e*1L:oB!  
{ flzHZH  
int nFileLength = -1; K3On8  
try{ "*N=aHsj  
URL url = new URL(siteInfoBean.getSSiteURL()); Y1Sfhs )  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T~JE.Y3B3  
httpConnection.setRequestProperty("User-Agent","NetFox"); WC *e#QP  
'980.  
W*/0[|n*  
int responseCode=httpConnection.getResponseCode(); w0!4@  
if(responseCode>=400) E[E7GsmqV  
{ `/\Z{j0_  
processErrorCode(responseCode); DU=rsePWE  
return -2; //-2 represent access is error R0_O/o+{  
} QGpAG#M9?  
568qdD`PS  
41Htsj  
String sHeader;  mZ^ev;  
L6E8A?>5rD  
dzn[4  
for(int i=1;;i++) -`<KjS  
{ Uth H  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); afNqK~  
//Utility.log(in.readLine()); *D6X&Hg&5  
sHeader=httpConnection.getHeaderFieldKey(i); rj> _L  
if(sHeader!=null) 8O_0x)X  
{ 5y%-K=d  
if(sHeader.equals("Content-Length")) Hd9vS"TN]  
{ 8,m3]Lg  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %}0B7_6B+@  
break; -T+7u  
} qTD^Vz V  
} ]31UA>/TI  
else Ccx1#^`  
break; 6 7{>x[  
} eg$y,Tx  
} `7mRUDz  
catch(IOException e){e.printStackTrace ();} +M/1,&  
catch(Exception e){e.printStackTrace ();} g&oAa;~o  
GoTJm}[N P  
:\<D q 71  
Utility.log(nFileLength); r#;GVJR6  
H@%Y"iIUP  
W{z{AxS  
return nFileLength; Yl#|+xYA5[  
} jJOs`'~Q\  
4UV<Q*B\F  
d?Y|w3lB  
//保存下载信息(文件指针位置) U81--'@y  
private void write_nPos() 4Cn% h)w  
{ 4>I >y@^  
try{ ^w(~gQ6|mP  
output = new DataOutputStream(new FileOutputStream(tmpFile)); okv`+VeA  
output.writeInt(nStartPos.length); <yq kJ  
for(int i=0;i<nStartPos.length;i++) ]`,jaD  
{ ~R!M.gY[rK  
// output.writeLong(nPos); /-v6jiM  
output.writeLong(fileSplitterFetch.nStartPos); |{en) {:  
output.writeLong(fileSplitterFetch.nEndPos); .\6q\7Ej  
} eKw!%97>  
output.close(); #lld*I"d  
} Un[ 0or  
catch(IOException e){e.printStackTrace ();} 9KgGK cy%  
catch(Exception e){e.printStackTrace ();} Gi=s|vt  
} Jv+N/+M47  
yy*8Aw}  
jFr[T  
//读取保存的下载信息(文件指针位置) 1O{(9nNj  
private void read_nPos() xS>d$)rIj  
{ 2uln)]  
try{ uz%<K(:Ov  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7yM"G$  
int nCount = input.readInt(); |2t1m 6\j  
nStartPos = new long[nCount]; QO&{Jx.^[  
nEndPos = new long[nCount]; _hz}I>G@B  
for(int i=0;i<nStartPos.length;i++) m2|%AD  
{ 6 J B"qd  
nStartPos = input.readLong(); & uMx*TTY  
nEndPos = input.readLong(); d[7B,l:RN  
} Vw>AD<Rl  
input.close(); !`h^S)$  
} >nqCUhS   
catch(IOException e){e.printStackTrace ();} Jdc{H/10  
catch(Exception e){e.printStackTrace ();} NZW)$c'  
} .%x%b6EI  
CNkI9>L=W`  
2f8\Osn>m  
private void processErrorCode(int nErrorCode) }\$CU N  
{ BD.>aAi!  
System.err.println("Error Code : " + nErrorCode); b$W~w*O   
} d(X/N2~g  
HkL`- c0  
"z6 xS;  
//停止文件下载 E'ay @YAp  
public void siteStop() HZJ)q`1E  
{ %UXmWXF4$  
bStop = true; P]mJ01@'  
for(int i=0;i<nStartPos.length;i++) mY 1Gm|  
fileSplitterFetch.splitterStop(); ]o<&Q52|  
M8{J  
{IgL H`@  
} MX )mm^A  
} ]I<w;.z  
//负责部分文件的抓取 u"s@eN  
**FileSplitterFetch.java `Hp=1a  
*/  gmW-#.  
package NetFox; m*f"Y"B.1I  
=euMOs  
.X](B~\!  
import java.io.*; 6a!b20IZh  
import java.net.*; V<&^zIJUR  
"pInb5F  
089 <B& <  
public class FileSplitterFetch extends Thread { ]p-x ds#d  
/a7N:Z_Bz  
xMr=tU1C  
String sURL; //File URL 2K VX  
long nStartPos; //File Snippet Start Position o^8Z cN>  
long nEndPos; //File Snippet End Position 6F8TiR&  
int nThreadID; //Thread's ID vi; yT.  
boolean bDownOver = false; //Downing is over _X]\#^UiO2  
boolean bStop = false; //Stop identical 3o^~6A  
FileAccessI fileAccessI = null; //File Access interface ~LF1$Cai  
rf=oH }  
%F2T`?t:  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 57jDsQAj  
{ %)#yMMhR  
this.sURL = sURL; UY}EW`$#m  
this.nStartPos = nStart; Q u_=K_W  
this.nEndPos = nEnd; !~_6S*~  
nThreadID = id; qF3s&WI  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l0K_29^  
} ' TO/i:{\  
L}UrI&]V$:  
EL^j}P  
public void run() 3S=$ng  
{ +|6E~#zklY  
while(nStartPos < nEndPos && !bStop) Sah!|9  
{ 9 Eqv^0u  
%{B4M#~  
U7xKu75G1  
try{ %zYTTPLZ  
URL url = new URL(sURL); &~'^;hy=  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cXIuGvE&=  
httpConnection.setRequestProperty("User-Agent","NetFox"); '>:%n  
String sProperty = "bytes="+nStartPos+"-"; t;b1<TLn0  
httpConnection.setRequestProperty("RANGE",sProperty); _+ERX[i  
Utility.log(sProperty); nU23D@l  
C {G647  
Zjn![  
InputStream input = httpConnection.getInputStream(); #SR )tU  
//logResponseHead(httpConnection); 1B`JvNtd  
tpQ8 m(  
j)mi~i*U  
byte[] b = new byte[1024]; xgJyG.?  
int nRead; G7k.YtW  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \=j|ju3  
{ :a*F>S!  
nStartPos += fileAccessI.write(b,0,nRead); LM*m> n*  
//if(nThreadID == 1) :Tdl84   
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +a|u,'u  
} asL!@YE  
>a)6GZ@  
JpZ3T~Wrf  
Utility.log("Thread " + nThreadID + " is over!"); 0IxHB|^$  
bDownOver = true; 98Im/v  
//nPos = fileAccessI.write (b,0,nRead); SD.c 9  
} K_}81|=  
catch(Exception e){e.printStackTrace ();} ^:2>I$  
} &`}ACTY'P  
} /rnP/X)T  
R_duPaWc@  
fO}Y$y\q  
//打印回应的头信息 P,bis7X.  
public void logResponseHead(HttpURLConnection con) _Kv;hR>  
{ IF kU8EK&B  
for(int i=1;;i++) _/5xtupxE  
{ keS%w]87  
String header=con.getHeaderFieldKey(i); l<p6zD$l  
if(header!=null) &t@|/~%[  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t<yOTVah  
Utility.log(header+" : "+con.getHeaderField(header)); 6Z!OD(/e  
else rp!>rM] s  
break; V&R_A~<T  
} fvM|Jb  
} vqRW^>~-B  
Q@- h  
k-8$ 43  
public void splitterStop() WO+_ |*&  
{ 4p]hY!7  
bStop = true; x<>In"QV  
} q&@q /9kz  
.xg, j{%(  
K~ VUD(  
} _j?/O)M c  
}>?"bcJ  
k2DBm q;  
/* |\/V1  
**FileAccess.java !z_VwZ#,  
*//文件访问(定位,写) 5uD'Kd$H  
package NetFox; J-Wphc!m  
import java.io.*; 3ms{gZbw  
AjMx\'(C  
Y -G;;~  
public class FileAccessI implements Serializable{ K2ry@haN  
8p.O rdp  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ek]CTUl*  
RandomAccessFile oSavedFile; d1/uI^8>  
long nPos; Q);^gV  
/Avl&Rd  
E{E%nXR)  
public FileAccessI() throws IOException :\,3=suWq  
{ X-J<gI(Y  
this("",0); Ng1uJa[k!d  
} XkuZ2(  
yWZ%|K~$  
qb$f,E[  
public FileAccessI(String sName,long nPos) throws IOException j~`rc2n%  
{ =@go;,"  
oSavedFile = new RandomAccessFile(sName,"rw"); KHt.g`1:R  
this.nPos = nPos; `+EjmY  
oSavedFile.seek(nPos); pYaq1_<+  
} YJ~3eZQ  
qJLtqv  
pax;#*QcQ  
public synchronized int write(byte[] b,int nStart,int nLen) C]DvoJmBs  
{ @G0j/@v  
int n = -1; uNG?`>4>  
try{ \&5t@sC  
oSavedFile.write(b,nStart,nLen); CDgu`jj%]  
n = nLen; %yP*Vp,W  
} ^FN(wvqb8  
catch(IOException e) \F8*HPM=*  
{ $K*&Wdo  
e.printStackTrace (); tJ@5E^'4  
} \k)(:[^FY  
|csR"DOqz  
mdPEF)-  
return n; PV/S zfvIq  
} Mwd(?o  
o;2QZ"v  
~$Pz`amT|  
} FT.;}!"l  
Oj^qh+r  
J,]U"+;H  
/* 5<KY}  
**SiteInfoBean.java rg{|/ ;imT  
*/ |HMpVT-;j  
package NetFox; Z4@GcdZ  
*WpDavovyB  
i& ybvTl  
public class SiteInfoBean { =)9@rV&~  
1b-_![&]1  
h?ZxS  
private String sSiteURL; //Site's URL x"QZ}28(t  
private String sFilePath; //Saved File's Path FZ^j|2.L*  
private String sFileName; //Saved File's Name yZ]u{LJS  
private int nSplitter; //Count of Splited Downloading File JJ$q*  
9Lv"|S`5W_  
$C8nPl' 7  
public SiteInfoBean() Wa+q[E  
{//nSplitter的缺省值为5 V_Oj?MMp n  
//default value of nSplitter is 5 >gFEA0-  
this("","","",5); %wuD4PRK  
} ]EZiPW-uy  
MUfhk)"  
@>sZ'M2mq  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1O,<JrE+-  
{ V,qc[*_3  
sSiteURL= sURL; mh=YrDU+L  
sFilePath = sPath; 2RC|u?+@  
sFileName = sName; P\R#!+FgW8  
this.nSplitter = nSpiltter; NLA/XZ  
q2C._{ 0'  
`c~J&@|  
} ;VAHgIpx;  
oWo/QNw9  
&KS*rHgt?  
public String getSSiteURL() !+# pGSk  
{ J"Z=`I)KON  
return sSiteURL; 5x:dhkW  
} @fSBW+  
=1'vXPv`  
fNnemn@>  
public void setSSiteURL(String value) @XL5$k[Y  
{ d`+@ _)ea  
sSiteURL = value; n^2p jTkl  
} r1)@ 7Nt  
BQfq]ti  
t/TWLhx/  
public String getSFilePath() +__PT4ps  
{ ^<VJ8jk<  
return sFilePath; [|!A3o  
} K7CrRT3>6  
IDIok~B=e  
;9rS[$^$O  
public void setSFilePath(String value) "bC1dl<  
{ k6?;D_dm  
sFilePath = value; [R~`6  
} nPU=n[t8O  
J*} warf&  
s}3`%?,6y  
public String getSFileName() L d;))e  
{ qXw^y  
return sFileName; Ob#d;F  
} uVn"'p-  
OmR) W'  
X5gI'u  
public void setSFileName(String value) exHg<18WSe  
{ y]e[fZ`L  
sFileName = value; R ]! [h  
} -)p S\$GC  
rV0X*[]J>  
t/57LjV  
public int getNSplitter() }pMd/|A,  
{ 9cwy;au  
return nSplitter; V|n}v?f_q  
} ?8GggJC  
p&nPzZQL(  
;"K;D@xzh]  
public void setNSplitter(int nCount) %7y8a`}  
{ /5$;W 'I  
nSplitter = nCount; /)<x<7FKW  
} ym =7EY?o  
} Y%1 94fY$  
-0>gq$/N=^  
+338z<'Z!  
/* }@XokRk  
**Utility.java JE<w7:R&  
*/ Sbp].3^j  
package NetFox; W:gpcR]>  
CVy\']  
nde_%d$  
public class Utility { W Y]   
+\_c*'K>  
6B=: P3Y  
public Utility() h7"c_=w+  
{ j*' +f~ A  
p"UdD  
L<62-+e`  
} o<8('j   
e>] gCa  
//线程睡眠 =+z+`ot  
public static void sleep(int nSecond) Z.l4<  
{ S<Os\/*  
try{ w$##GM=Tq  
Thread.sleep(nSecond); A 6IrA/b  
} bQlvb  
catch(Exception e) g]Jt (aYK  
{ /L yoTBG  
e.printStackTrace (); BtA_1RO  
} Rl/5eE8  
} 5w+KIHhN|  
tg%#W `  
//日志 @/,:". SM  
public static void log(String sMsg) ouE/\4'NB  
{ wr-/R"fX  
System.err.println(sMsg); [Xyu_I-c  
} U5RLM_a@M  
>_J9D?3S  
SIridZ*%  
public static void log(int sMsg) $Vp*,oRL  
{ ! *eDT4a  
System.err.println(sMsg); Oo0SDWI`(  
} !7hjA=0  
} 4'wbtE|  
qeUT]* w  
[p+-]V  
/* C==yl"w  
**TestMethod.java YWFq&II|Z  
*/ uo8[,'  
package NetFox; omMOA  
Cvp!(<<gK  
ZccvZl ;b  
public class TestMethod { 9?XQB%44  
4=~+B z  
n "bii7h  
public TestMethod() H[_i=X3-~  
{ ///xx/weblogic60b2_win.exe  mPL0s  
try{ >I@VHl O  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ? Xl;>}zj  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U EjP`  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;aN_!! r  
fileFetch.start(); 7 'q *(v  
} QdrZi.qKH  
catch(Exception e){e.printStackTrace ();} smUSR4VK  
/rIyW?& f  
lQM&q  
} :N^+!,i  
z ub"Ap3  
b} 0G~oLP  
public static void main(String[] args) rez )$  
{ V1&qgAy~  
new TestMethod(); L</k+a?H!  
} RY .@_{  
} {vq| 0t\-  
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