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http断点续传简单实现(java)

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/* [uqr  
**SiteFileFetch.java CxaI@+  
*/ 7Z]?a  
package NetFox; =z5=?  
import java.io.*; 0D4 4  
import java.net.*; Pq~#SxA~  
W\<OCD%X  
rMG[,:V  
public class SiteFileFetch extends Thread { WClprSl8  
{C`M<2W]  
=KR^0<2r  
SiteInfoBean siteInfoBean = null; //文件信息Bean GX19GI@k  
long[] nStartPos; //开始位置 K'8o'S_bF  
long[] nEndPos; //结束位置 ';.TQ_I7Y  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 hK4ww"-  
long nFileLength; //文件长度 7]u_  
boolean bFirst = true; //是否第一次取文件 ,FYA*}[  
boolean bStop = false; //停止标志 :Dr4?6hdr  
File tmpFile; //文件下载的临时信息 CNuE9|W(vI  
DataOutputStream output; //输出到文件的输出流 gz'{l[  
Sy.%>$z  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) )+ G0m,n  
public SiteFileFetch(SiteInfoBean bean) throws IOException K&._fG  
{ .))k  
siteInfoBean = bean; M97+YMY)  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); uR")@Tc  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); sfG9R"  
if(tmpFile.exists ()) LU*mR{B  
{ :zC=JvKT  
bFirst = false; MeV4s%*O+  
read_nPos(); i{:?Iw 'ay  
} ^38k xwh  
else 9&kY>M>z0  
{ n}%_H4t  
nStartPos = new long[bean.getNSplitter()]; x2~fc  
nEndPos = new long[bean.getNSplitter()]; r_ 9"^Er  
} 'lC=k7@x  
( K-7z  
P[`>*C\9c  
z 4. |N  
} 8oHIXnK  
mFpj@=^_G  
y54RD/`-  
public void run() -[=@'N P  
{ LUx'Dm"  
//获得文件长度 %LdBO1D0  
//分割文件 VKXB)-'L  
//实例FileSplitterFetch " d~M \Az  
//启动FileSplitterFetch线程  r+]a  
//等待子线程返回 Qc9[/4R>  
try{ z,qNuv"W  
if(bFirst) :'H}b*VWx  
{ -K^(L #G  
nFileLength = getFileSize(); |Qpo[E }a  
if(nFileLength == -1) ;(g"=9e  
{ D_f :D^  
System.err.println("File Length is not known!"); K=sk1<>)m  
} ciH TnC  
else if(nFileLength == -2) Exi#@-  
{ >hnhV6ss  
System.err.println("File is not access!"); O>wGJ.  
} 5*"WS $  
else ) \cnz  
{ R8% u9o  
for(int i=0;i<nStartPos.length;i++) y(Pv1=e  
{ k3 '5Ei  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); \>/AF<2"  
} odeO(zuU  
for(int i=0;i<nEndPos.length-1;i++) ~8Ef`zL  
{ ,E(M<n|.  
nEndPos = nStartPos[i+1]; wGz_IL.D  
} w@N)Pu  
nEndPos[nEndPos.length-1] = nFileLength; $iy(+}  
} 6>d 3*   
} '~6l 6wi  
SZgan  
+I~U8v-  
//启动子线程 tN)Vpb\J  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ' #r^W2  
for(int i=0;i<nStartPos.length;i++) HBa6Y&)<  
{ G)5Uiu:^X  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /X\:3P  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H,fVF837  
nStartPos,nEndPos,i); 8/9YR(H3H  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j1@PfKh  
fileSplitterFetch.start(); FZ% WD@=  
} <dY{@Cgw=  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :)Nk  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t1l4mdp  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Gm\jboef]  
nEndPos = " + nFileLength); zt )WX9  
// fileSplitterFetch[nPos.length-1].start(); vns Mh  
N jA\*M9  
4,6?sTuX  
//等待子线程结束 xO 1uHaL  
//int count = 0; Ac,bf 8C  
//是否结束while循环 $)O\i^T  
boolean breakWhile = false; XOY\NMo  
41XXL$  
b@1";+(27  
while(!bStop) P6ugbq[x#e  
{ SQ`ec95',  
write_nPos(); 6}mSA@4&  
Utility.sleep(500); 6<Zk%[7t  
breakWhile = true; B{_-k  
|VX0o2  
H`U>ZJ.  
for(int i=0;i<nStartPos.length;i++) Su`] ku'  
{ Fc"+L+h@W  
if(!fileSplitterFetch.bDownOver) <C7/b#4>\  
{ m3b?f B  
breakWhile = false; nqujT8  
break; 3rv~r0  
} 3n TpL#  
} `XwKCI  
if(breakWhile) +?[iB"F  
break; v.]W{~PI2V  
htqC~B{1E  
.`N&,&H  
//count++; I* JSb9r  
//if(count>4) q}7(w$&  
// siteStop(); fL R.2vJ  
} ez*O'U  
cU=/X{&Om  
[IuF0$w=dj  
System.err.println("文件下载结束!"); |G>Lud  
} =^3B&qQNq  
catch(Exception e){e.printStackTrace ();} WPNvZg9*c  
} T ;JA.=I  
,Z]4`9c  
:j!N7c{  
//获得文件长度 +QFY. >KH  
public long getFileSize() d[Rs  
{ rexy*Xv`2p  
int nFileLength = -1; GI*2*m!u  
try{ 2Y{r2m|o  
URL url = new URL(siteInfoBean.getSSiteURL()); _M}}H3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |/p2DU2  
httpConnection.setRequestProperty("User-Agent","NetFox"); /H[!v:U  
q1o)l  
\wo'XF3:  
int responseCode=httpConnection.getResponseCode(); ID v|i.q3  
if(responseCode>=400) r*s)T`T}}  
{ #_OrS/H  
processErrorCode(responseCode); lw 9 rf4RF  
return -2; //-2 represent access is error cY\"{o"C  
} i/WiSwh:  
8Ow0A  
XB-l[4?  
String sHeader; be{tyV  
< {dV=  
naKB2y]l  
for(int i=1;;i++) 2(sq*!tX  
{ 5l(Q#pSX  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ) bGzsb1\  
//Utility.log(in.readLine()); q\6ZmKGnT  
sHeader=httpConnection.getHeaderFieldKey(i); Lv?e[GA  
if(sHeader!=null) )OcG$H NK  
{ *l4`2eqZ  
if(sHeader.equals("Content-Length")) Kf7v_T /  
{  ~/kx  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (|<.7K N  
break; vy330SQPo  
} QZ51}i  
} qy|si4IU8,  
else J deGQ  
break; O:,Fif?;  
} ]):kMRv  
} .FXn=4l'vV  
catch(IOException e){e.printStackTrace ();} DN;An0 {MK  
catch(Exception e){e.printStackTrace ();} ?rgk  
^aG=vXK`b  
uEKa  FRm  
Utility.log(nFileLength); Tb6c]?'U  
Fps.Fhm  
GT"gB$Mh  
return nFileLength; 7 V+rQ  
} ?]L:j  
\;s mH;m  
wm r8[n&c  
//保存下载信息(文件指针位置) ^yB>0/{)z  
private void write_nPos() U$(AZ|0  
{ (GdL(H#IL  
try{ \hwz;V.J"  
output = new DataOutputStream(new FileOutputStream(tmpFile)); x GHS  
output.writeInt(nStartPos.length); RGim):1e  
for(int i=0;i<nStartPos.length;i++) "Aq-H g  
{ jFBnP,WQ  
// output.writeLong(nPos); o!+jPwEU  
output.writeLong(fileSplitterFetch.nStartPos); R\wG3Oxol  
output.writeLong(fileSplitterFetch.nEndPos); lx&ME#~  
} 7Q9zEd" d  
output.close(); \WeGO.i-  
} LMvsYc~]q  
catch(IOException e){e.printStackTrace ();} yXx}'=&!0  
catch(Exception e){e.printStackTrace ();} Wg+fT{[f|  
} j.@TPf*  
to  
'j+J?Y^  
//读取保存的下载信息(文件指针位置) A"@C }f  
private void read_nPos() {6yiD  
{ Dab1^H!KT  
try{ =K)au$BE|  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GUyc1{6  
int nCount = input.readInt(); EI29;  
nStartPos = new long[nCount]; $iA`_H`W  
nEndPos = new long[nCount]; v&EHp{8Qd  
for(int i=0;i<nStartPos.length;i++) 3Yd)Fm  
{ yU(k;A-  
nStartPos = input.readLong(); YrR}55V,  
nEndPos = input.readLong(); Uv06f+P(  
} e_BOzN~c  
input.close(); >#RXYDd  
} =kspHP<k  
catch(IOException e){e.printStackTrace ();} =y/VrF.bV  
catch(Exception e){e.printStackTrace ();} Tl!}9/Q5E:  
} h.6yI  
WlnI`!)d  
U9KnW]O%"  
private void processErrorCode(int nErrorCode) ,&sBa{0  
{ K6.*)7$#  
System.err.println("Error Code : " + nErrorCode); "(+ >#  
} 46dh@&U  
K/y#hP  
*}\!&Zk"  
//停止文件下载 [lsr[`SJ<  
public void siteStop() q lL6wzq,  
{ Iky'x[p,D  
bStop = true; ,!f*OWnZ  
for(int i=0;i<nStartPos.length;i++) >4.{|0%ut  
fileSplitterFetch.splitterStop(); j!;?=s  
yS#LT3>l  
)h ~MIpWR  
} a"{tqNc  
} ?hS n)  
//负责部分文件的抓取 ) tGC&l+?/  
**FileSplitterFetch.java o(. PxcD  
*/ V$wf;v0d(  
package NetFox; ?.:C+*+  
}XiS:  
J}coWjw`q  
import java.io.*; D'>yu"  
import java.net.*; 1(Kd/%]{  
;&|ja]r  
TZq']Z)#  
public class FileSplitterFetch extends Thread { :_tsS)Q2m  
.(  vS/  
5M~\'\;  
String sURL; //File URL IiACr@[?e  
long nStartPos; //File Snippet Start Position :Q\b$=,:  
long nEndPos; //File Snippet End Position C,w$)x5kls  
int nThreadID; //Thread's ID ztG_::QtG]  
boolean bDownOver = false; //Downing is over DB yRP-TH  
boolean bStop = false; //Stop identical n2R{$^JxO  
FileAccessI fileAccessI = null; //File Access interface }Y5Sf"~M  
gU Cv#:  
,c6ID|\  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Gt[!q\^?  
{ EeKEw Sg  
this.sURL = sURL; S2" p(  
this.nStartPos = nStart; laqW {sX^5  
this.nEndPos = nEnd; X+{4,?04+  
nThreadID = id; cT8jG ,+"}  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }@V(y9K  
} R tn.cSd  
5isejR{r  
 7[55  
public void run() Ku_`F2Q  
{ 77OH.E|$  
while(nStartPos < nEndPos && !bStop) ,k/*f+t  
{ p~28?lYv  
-lyT8qZ:(  
4.7ePbk[E  
try{ S"w$#"EJA  
URL url = new URL(sURL); kzGD *  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RaAi9b[/S  
httpConnection.setRequestProperty("User-Agent","NetFox"); `ejE)VL=8h  
String sProperty = "bytes="+nStartPos+"-"; 2_0OSbFv'P  
httpConnection.setRequestProperty("RANGE",sProperty); pHY~_^B4&  
Utility.log(sProperty); R{3f5**0  
z4 8,{H6h  
j3~:\H  
InputStream input = httpConnection.getInputStream(); LI?rz<H!D  
//logResponseHead(httpConnection); o\8yYX  
0?ZJJdI3  
j ij:}.d6  
byte[] b = new byte[1024]; ekfD+X  
int nRead; "-vm=d~\  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }}Eko7'^  
{ }(dhXOf\q  
nStartPos += fileAccessI.write(b,0,nRead); Fp-d69Npo  
//if(nThreadID == 1) Ud:v3"1  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rU5gQq;  
} (M6B$:  
OUe@U;l{Z  
Rw*l#cr=.  
Utility.log("Thread " + nThreadID + " is over!"); &D uvy#J  
bDownOver = true; IyYC).wU}  
//nPos = fileAccessI.write (b,0,nRead); T<DQi  
} _I~W!8&w>  
catch(Exception e){e.printStackTrace ();} CO1D.5  
} 1A">tgA1  
} ,~gY'Ql  
o8RagSIo8  
[a 5L WW  
//打印回应的头信息 NZ'S~Lr   
public void logResponseHead(HttpURLConnection con) ~j mHzF kQ  
{ ld4QhZia  
for(int i=1;;i++) eM+]KG)}  
{ xe2Ap[Y'M  
String header=con.getHeaderFieldKey(i); _;{n+i[  
if(header!=null) "a;JQ:  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k#ED#']N  
Utility.log(header+" : "+con.getHeaderField(header)); Q! ]  
else v-X1if1%  
break; 4)-LlYS_d<  
} ;p/RS#  
} G1vWHa7n;f  
91r#lDR  
myFj w@  
public void splitterStop() Z= dEk`  
{ ^x4I  
bStop = true; ZyT9y  
} m ,)4k&d  
"kz``6C  
E:(flW=  
} ^:\|6`{n  
0eQyzn*98  
rcPP-+XW  
/* W{At3Bfy  
**FileAccess.java 0CQ\e1S,#  
*//文件访问(定位,写) 1Qtojph  
package NetFox; &n6mXFF#>P  
import java.io.*; V(A6>0s$|  
7<oLe3fbM  
vN-#Ej. u  
public class FileAccessI implements Serializable{ v1QE|@  
fnG&29x  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I7nt<l!  
RandomAccessFile oSavedFile; *;(LKRV  
long nPos; ioIUIp+B~u  
L=Fm:O'#2  
# h]m8  
public FileAccessI() throws IOException ea=@r Ng  
{ /fWVgyW> 6  
this("",0); 1 +O- g  
} Ti!j  
D!ToCVos  
/);cl;"  
public FileAccessI(String sName,long nPos) throws IOException f:GZb?Wyd  
{ dOqn0Z  
oSavedFile = new RandomAccessFile(sName,"rw"); DHW;*A-  
this.nPos = nPos; DT8|2"H  
oSavedFile.seek(nPos); >0=`3X|Y7  
} tEf_XBjKV  
3lqR(Hh3  
V{O,O,*  
public synchronized int write(byte[] b,int nStart,int nLen) .%h.b6^  
{ B9/x?Jv1  
int n = -1; '%yWz)P  
try{ * 'WzIk2  
oSavedFile.write(b,nStart,nLen); } '.l'%  
n = nLen; #qGfo)  
} ;+g p#&i`  
catch(IOException e) :Oo(w%BD]  
{ /-b)`%Q|Y  
e.printStackTrace (); KY<>S/  
} B@Ez,u5  
+#}I^N  
7@$Hua,GY  
return n; |Ma"B4  
} 13I 7ah  
{j+w|;dZF  
p\wE})mu  
} # nwEF QA  
AdesR-e$R  
DmM<Kkg.J  
/* lplEQ]J|  
**SiteInfoBean.java WLQm|C,  
*/ P&V,x`<Z  
package NetFox; mEmznA  
_$s9o$8$  
L"&j(|{  
public class SiteInfoBean { XL>c TM  
'^'vafs-/@  
".O+";wk  
private String sSiteURL; //Site's URL 3XYCtp8  
private String sFilePath; //Saved File's Path a?.hvI   
private String sFileName; //Saved File's Name J4#t1P@Na  
private int nSplitter; //Count of Splited Downloading File f ."bq43(  
~C6d5\  
?1K|.lr  
public SiteInfoBean() 3xWeN#T0  
{//nSplitter的缺省值为5 v}!eJzeH  
//default value of nSplitter is 5 Zj99]4?9  
this("","","",5); 8 sZ~3  
} \Y_2Z /  
FN NEh  
!jL|HwlA  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) UB }n=  
{ v=EV5#A  
sSiteURL= sURL; 0'wB':v  
sFilePath = sPath; qvy~b  
sFileName = sName; cu5Yvp  
this.nSplitter = nSpiltter; "jH=O(37  
"G-} wt+P  
\/g.`Pe  
} L!Iu\_{q  
eEePK~%c  
<RS@,  
public String getSSiteURL() laG@SV  
{ l&S2.sC  
return sSiteURL; 5:6as^i:b  
} v*SSc5gFG  
AA"?2dF  
obKWnet  
public void setSSiteURL(String value) LFvKF.  
{ zs<W>gBq  
sSiteURL = value; (= } cc  
} Mo\LFxx>4{  
v=zqj}T  
:'9%~q.D4  
public String getSFilePath() HpSmB[WF  
{ o?$kcI4  
return sFilePath; ]ppi962Z  
} y.AVH`_u  
\Z-T)7S  
kRo dC(f @  
public void setSFilePath(String value) 4NT zK  
{ _\hZX|:]  
sFilePath = value; G=W!$(:  
} ~s{yh-B  
^m.QW*  
3o&PVU? Q  
public String getSFileName() j/`- x  
{ :Fz;nG-G  
return sFileName; ?piv]Z  
} { </MC`  
4bLk+EY4A  
SIv8EMGo  
public void setSFileName(String value) "jqC3$DKI  
{ >Ig%|4Hw  
sFileName = value; LW<DhMV  
} 7 ^7Rk  
g+;)?N*j  
47>IT  
public int getNSplitter() /` 891( f,  
{ 20750G  
return nSplitter; Oa~|a7`o  
} MG)wVS<d_  
M>W-lp^3  
,3l=44*  
public void setNSplitter(int nCount) Kk#g(YgNz  
{ Pw i6Ly`  
nSplitter = nCount; ]L#6'|W  
} 7?a@i; E<  
} T\ZWKx*#  
D%GB2-j R  
^j&'2n@ 9a  
/* /nEt%YYh;x  
**Utility.java mL/]an@Y  
*/ g"vg {Q  
package NetFox; =<mpZ'9gW  
 lc9aDt  
Jlw%t!Kx  
public class Utility { b* Ny  
0f~7n*XH  
u=NpL^6s<  
public Utility() 2<HG=iSf  
{ Z0*Lm+d9z  
y57]q#k  
CBw/a0Uck  
} EV{kd.=f  
'{=dEEi  
//线程睡眠 1-[~}  
public static void sleep(int nSecond) gM_z`H 5[!  
{ R\k= CoJJ  
try{ pwo5Ij,~q  
Thread.sleep(nSecond); ?&#z3c$}  
} KNT(lA0s  
catch(Exception e) a)J3=Z-  
{ #v!(uuq,  
e.printStackTrace (); EOJk7  
} "{>I5<:t  
} %"tLs%"7=P  
.2?tx OKh  
//日志 k[lYd k  
public static void log(String sMsg) EQZu-S`kv  
{ d~+8ui{-U  
System.err.println(sMsg); 8m,PsUp7  
} qjcy{@ j  
2,,zN-9mt  
9Fb|B  
public static void log(int sMsg) fFP>$  
{ T \%{zz_(  
System.err.println(sMsg); s`"o-w\$>  
} [P,YW|:n  
} C@+"d3  
3GVE/GtU  
)9'eckt  
/* %-ih$ZY  
**TestMethod.java l%"[857  
*/ k^3 ?Z2a  
package NetFox; Z#7T!/28  
*:t]|$;E\  
i!8 o(!I  
public class TestMethod { ~5Wr |qg%{  
'Gwa[ |6i  
wn*<.s  
public TestMethod() 0l-m:6  
{ ///xx/weblogic60b2_win.exe ghvF%-."1  
try{ mNkS!(L6  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,4dES|)sP  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?"MJ'u  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6<0-GD}M  
fileFetch.start(); +g36,!q  
} S%KY%hUt  
catch(Exception e){e.printStackTrace ();} *p!K9$4  
bz!9\D|h  
hKq <e%oVH  
} W\09h Z6  
r~q*E'n  
s+Qm/ h2  
public static void main(String[] args) Mazjn?f  
{ }`k >6B  
new TestMethod(); i8R.Wl$l  
} 8joJ e>9VJ  
} + $i-"^  
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