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http断点续传简单实现(java)

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/* fc>L K7M  
**SiteFileFetch.java #g!.T g'  
*/ j'K/22  
package NetFox; Ax}JLPz5'  
import java.io.*; _@/8gPT*i  
import java.net.*; ^LLzZnkcZ  
k9F=8q  
wy2 D;;  
public class SiteFileFetch extends Thread { Eh4= ZEX  
8q7b_Pq1U  
<gBA1oRz  
SiteInfoBean siteInfoBean = null; //文件信息Bean <OPArht  
long[] nStartPos; //开始位置 L}NSR  
long[] nEndPos; //结束位置 }<:}XlwT%  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 93hxSRw  
long nFileLength; //文件长度 ,2ar7 5Va  
boolean bFirst = true; //是否第一次取文件 1h5 Akq  
boolean bStop = false; //停止标志 C7AUsYM  
File tmpFile; //文件下载的临时信息 5F"jk d+  
DataOutputStream output; //输出到文件的输出流 9N3eN  
d'sZxU  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) kcx Ad   
public SiteFileFetch(SiteInfoBean bean) throws IOException x,Vr=FB  
{ kU`r)=1"  
siteInfoBean = bean; 2J;g{95z  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); /Ci<xmP  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ;A[Q2(w+  
if(tmpFile.exists ()) $ME)#(  
{ Kc(FX%3LU  
bFirst = false; 0m ? )ROaJ  
read_nPos(); :BT q!>s  
} syK^<xa  
else TS5Q1+hWHV  
{ 3R V R  
nStartPos = new long[bean.getNSplitter()]; cM7[_*Ot<m  
nEndPos = new long[bean.getNSplitter()]; rrv%~giU  
} LOJAWR9$^U  
[ikOb8 G#  
Z%\,w(o[h  
I<tm"?q0  
} 8\gjST*  
v.5+7,4  
BsJC0I(  
public void run() 4X|zmr:A  
{ xN%K^Tree  
//获得文件长度 :\U{_@?`%  
//分割文件 g=o4Q< #^y  
//实例FileSplitterFetch po7qmLq  
//启动FileSplitterFetch线程 @s^-.z  
//等待子线程返回 #3d(M  
try{ 7VI*N)OZ8  
if(bFirst) @\I#^X5lv  
{ pb=h/8R  
nFileLength = getFileSize(); \uMLY<]P  
if(nFileLength == -1) N}YkMJy  
{ TuqH*{NNy9  
System.err.println("File Length is not known!"); gPc=2  
} I++. ee  
else if(nFileLength == -2) 7t_^8I%[  
{ 8HdAFRw  
System.err.println("File is not access!"); -|\ZrE_h  
} ^sg,\zD 'X  
else sn>~O4"  
{ 01o4Th m  
for(int i=0;i<nStartPos.length;i++) >-{Hyx  
{ <rSF*  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ws^ np  
} 7J&4akT{9  
for(int i=0;i<nEndPos.length-1;i++) q"_QQ~  
{ pY$Q  
nEndPos = nStartPos[i+1]; Zj4Uak  
} GowH]MO  
nEndPos[nEndPos.length-1] = nFileLength; jlg(drTo  
} CVR3 A'  
} 5rUdv}.  
gltBC${7wZ  
@ur+;IK$  
//启动子线程 T9q-,w/j;  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7j)8Djzp|  
for(int i=0;i<nStartPos.length;i++) W`*r>`krVJ  
{ /5AJ.r  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r!{Up7uL  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FU<Jp3<%  
nStartPos,nEndPos,i); 7vj2 `+r.  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .XhrCi Z  
fileSplitterFetch.start(); 0Fr?^3h  
} @AuO`I@p=  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?b5 ^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <_KIK  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -n5)w*b,  
nEndPos = " + nFileLength); VOh4#%Vj  
// fileSplitterFetch[nPos.length-1].start(); @$K"o7+]   
F1Bq$*'N$w  
y L~W.H  
//等待子线程结束 -1@<=jX3_  
//int count = 0; $ o#V#  
//是否结束while循环 `pZm?}K  
boolean breakWhile = false; fLAw12;^  
;P&OX5~V  
N$:8 ,9.z  
while(!bStop)  1ZB"EQ  
{ _8agtQ:<  
write_nPos(); :S(ZzY Q  
Utility.sleep(500); n@[O|?S  
breakWhile = true; %GIr&V4|  
MR.'t9m2L  
"Os_vlapHo  
for(int i=0;i<nStartPos.length;i++) ps DetP  
{ u,Kly<0j  
if(!fileSplitterFetch.bDownOver) S?BG_J6A7  
{ 26x[X.C:  
breakWhile = false; 1 I",L&S1  
break; Ef13Q]9|  
} &UlWCOo8  
} YkQd  
if(breakWhile) eO[b1]WLP  
break; g9 5`.V}  
@2v_pJy^  
2gVm9gAHUd  
//count++; 2SR:FUV/  
//if(count>4) t#eTV@-  
// siteStop(); !m?-!:  
} d9|<@A  
.Rf_Cl  
"`1bA"E  
System.err.println("文件下载结束!"); P J[`|  
} 'a.qu9PJ  
catch(Exception e){e.printStackTrace ();} 2Q:+_v  
} {3vNPQJ  
fL7xq$K  
0%I=d  
//获得文件长度 I4?5K@a  
public long getFileSize() D*|Bb?  
{ ! #2{hQRu  
int nFileLength = -1; ayF\nk4b  
try{ .y:U&Rw4  
URL url = new URL(siteInfoBean.getSSiteURL()); \mlqO[ S  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0h7r&t%YsV  
httpConnection.setRequestProperty("User-Agent","NetFox"); >!)DM]Ri  
Jma1N;d  
`%WU8Yv  
int responseCode=httpConnection.getResponseCode(); >Wg hn:^  
if(responseCode>=400) ls)%c  
{ :tv,]05t  
processErrorCode(responseCode); >`ZyG5  
return -2; //-2 represent access is error  | (_  
} HT1!5  
A1zjPG&]  
Bo%NFB;  
String sHeader; ]~hk6kS8Q  
!0mI;~q|F  
 U}j0D2  
for(int i=1;;i++) -_eLf#3  
{ $5Ff1{  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ))'<_nD  
//Utility.log(in.readLine()); ~zNAbaC+>t  
sHeader=httpConnection.getHeaderFieldKey(i); XAL1|] S  
if(sHeader!=null) iTU5l5Uz  
{ fkNbS  
if(sHeader.equals("Content-Length")) xe&i^+i  
{ 3WIk  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O/(xj2~$ J  
break; vTw>JNVI  
} GYUn6P  
} yd`mG{Z  
else 'u<juFr  
break; y;@:ulv[  
} "o}+Ciul  
} =P #]  
catch(IOException e){e.printStackTrace ();} Aj+F |l  
catch(Exception e){e.printStackTrace ();} 1 Nd2{(  
7g}w+p>  
x>`%DwoRI  
Utility.log(nFileLength); (mtk 4  
9o:Lz5 o  
t"/q]G5  
return nFileLength; HBx=\%;n  
} #';:2Nyq  
xbYi.  
dT1H  
//保存下载信息(文件指针位置) {8,J@9NU  
private void write_nPos() Y#$%iF  
{ B%+T2=&$7  
try{ +@iA;2&  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]^K 4i)\  
output.writeInt(nStartPos.length); >%8KK|V{  
for(int i=0;i<nStartPos.length;i++) E#t>Qn  
{ =]Jd9]vi  
// output.writeLong(nPos); .$)  
output.writeLong(fileSplitterFetch.nStartPos); 2Ny"O.0h  
output.writeLong(fileSplitterFetch.nEndPos); 7,9=uk>0\  
} WKa~[j|-K  
output.close(); R/>@ +  
} a\ YV3NJ/A  
catch(IOException e){e.printStackTrace ();} PQ$%H>{  
catch(Exception e){e.printStackTrace ();} +-CtjhoS  
} ;)^`3`  
N7 $I^?<  
EV@X*| w  
//读取保存的下载信息(文件指针位置) V~;1IQd{  
private void read_nPos() ve2u=eQ1  
{ bTs?!~q  
try{ yT9@!]^L  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); % 0+j?>#X  
int nCount = input.readInt(); i5?q,_  
nStartPos = new long[nCount]; R>mmoG}MQ[  
nEndPos = new long[nCount]; ]R9HyCl&a6  
for(int i=0;i<nStartPos.length;i++) ! lc[  
{ _1!OlQ  
nStartPos = input.readLong(); R)ITy!z  
nEndPos = input.readLong(); b-Q>({=i  
} !.(P~j][  
input.close(); I( 7NQ8H x  
} Hm'=aff6A  
catch(IOException e){e.printStackTrace ();} \WB<86+z  
catch(Exception e){e.printStackTrace ();} 3Xy-r=N.l  
} 3c6b6  
oij}'|/Jc  
)6,=f.%  
private void processErrorCode(int nErrorCode) z]`k#O%%)  
{ .I0qGg  
System.err.println("Error Code : " + nErrorCode); Jk=I^%~  
} _k ~KZ;l  
l &5QZI0I  
v"XGCi91L  
//停止文件下载 Ay w ;N  
public void siteStop() fbKkq.w  
{ !1{e|p 7  
bStop = true; q0R -7O(  
for(int i=0;i<nStartPos.length;i++) EkNunCls  
fileSplitterFetch.splitterStop(); @? QoF#D  
jeH~<t{  
E`de7  
} n'kG] Q  
} !1 8clL  
//负责部分文件的抓取 aa#Y=%^  
**FileSplitterFetch.java =sJ7=39  
*/ H0`]V6+<f  
package NetFox; -0{r>,&Mm  
#S*/bao#  
9V@V6TvW>&  
import java.io.*; G5aieD.#  
import java.net.*; K<qk.~ S  
+:!7L= N#  
q[W 0 N >  
public class FileSplitterFetch extends Thread { Q&=w_Wc  
jun_QiU:2  
1A G<$d5U|  
String sURL; //File URL $ig0j`  
long nStartPos; //File Snippet Start Position D"rK(  
long nEndPos; //File Snippet End Position T)TfB(  
int nThreadID; //Thread's ID 8xV9.4S  
boolean bDownOver = false; //Downing is over $r8 ^0ZRr  
boolean bStop = false; //Stop identical "(z5{z?S  
FileAccessI fileAccessI = null; //File Access interface vyX\'r.~7  
r6} |hpJ8  
Et/\xL  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @As[k2  
{ *%fi/bimG  
this.sURL = sURL; v>Yb/{A  
this.nStartPos = nStart; vK\%%H  
this.nEndPos = nEnd; Y^7$t^&  
nThreadID = id; !1DKLQ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ``Dq  
} s!&#c`=  
9c#+qH  
{kCw+eXn?  
public void run() p~^D\jR.  
{ 'H&2HXw&2  
while(nStartPos < nEndPos && !bStop) ]#l/2V1  
{ o(LFh[  
PHXZ=A+  
&cHV7  
try{ `c5"d  
URL url = new URL(sURL); Q$1bWUS&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Raxrb=7  
httpConnection.setRequestProperty("User-Agent","NetFox"); G{ sOR  
String sProperty = "bytes="+nStartPos+"-"; ^*8G8'k;$  
httpConnection.setRequestProperty("RANGE",sProperty); 4C-jlm)V  
Utility.log(sProperty); E2@65b$  
Q<'nE  
Ba*,-i3ZK  
InputStream input = httpConnection.getInputStream(); m4&h>9. 8  
//logResponseHead(httpConnection); gL[yA?GoM  
"2P&X  
WEQ1 Seq  
byte[] b = new byte[1024]; m~P CB_ifW  
int nRead; V4P; 5[  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Gh}LlX!w  
{ ,5kKimTt  
nStartPos += fileAccessI.write(b,0,nRead); 7;sj%U^'l  
//if(nThreadID == 1) bRJMYs  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5eoska#y   
} / !Wu D\B  
}Q?c"H!/  
Hh-+/sO~"  
Utility.log("Thread " + nThreadID + " is over!"); %?uc><&?e  
bDownOver = true; ;WM"cJo9  
//nPos = fileAccessI.write (b,0,nRead); $Ifmc`r1  
} cU@SIJ)  
catch(Exception e){e.printStackTrace ();} [}/LD3  
} u7\J\r4,+  
} /#-C4"|  
R)z4n  
{QZUDPPR  
//打印回应的头信息 *4xat:@{{  
public void logResponseHead(HttpURLConnection con) SHbtWq}T  
{ ~\.w^*$#Y  
for(int i=1;;i++) ^3{TZ=_;|  
{ N#7QzB9]  
String header=con.getHeaderFieldKey(i); #PanfYR  
if(header!=null) e8]\U/  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8V)^R(\;  
Utility.log(header+" : "+con.getHeaderField(header)); r>"   
else *x])Y~oQ  
break; ?^$MRa:D  
} oA7;.:3  
} V7[zAq  
LbG_z =A  
J'fQW<T4wU  
public void splitterStop() .0iQad&duh  
{ U.XNv-M  
bStop = true; e~@ [18  
} 'fF;(?  
wX[8A/JPD  
)V ;mwT!Q  
} MHai%E  
n\5RAIg  
r77PQQD T  
/* 'u_t<F ]b  
**FileAccess.java Ikiib WQL+  
*//文件访问(定位,写) T/xp?Vq6/  
package NetFox; K]|> Et`  
import java.io.*; bKQ"ax>6p  
rN<b?KE  
:GW&O /Yo  
public class FileAccessI implements Serializable{ 1_ C]*p  
%1O[i4s:-  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H5]^ 6 HwX  
RandomAccessFile oSavedFile; 2eC(Ijq[a  
long nPos; !V\Q<So<  
T G{k0cdOT  
ZAUQJS 91E  
public FileAccessI() throws IOException 92d6U2T4&  
{ 4Hn`'+b  
this("",0); no] z1D  
} ks97k8B  
80&.JP.  
TJ'[--  
public FileAccessI(String sName,long nPos) throws IOException +$(2:S*r  
{ K+8-9$w6  
oSavedFile = new RandomAccessFile(sName,"rw"); Q7C;1aO  
this.nPos = nPos; vR=6pl$|~~  
oSavedFile.seek(nPos); f=!VsR2o  
} {g~bQ2wDC  
z=_Ef3`M  
;VNMD 6H  
public synchronized int write(byte[] b,int nStart,int nLen) Nl9I*x^e  
{ 7&"n`@(.!  
int n = -1; }X_;X_\3;'  
try{ T4 N~(Fi)  
oSavedFile.write(b,nStart,nLen); R8UYP=Kp  
n = nLen; mp?78_I)  
} 3=$q  
catch(IOException e) >sjhA|gXk  
{ /K{9OT@>  
e.printStackTrace (); ""h)LUrl  
} )a3J9a;ZS0  
,H2D  
E+tB&  
return n; N, *m ,  
} D?,#aB"  
M$d%p6Cv  
G4;3cT3'  
} aKlUX  
Cb@3M"1:  
1q3( @D5~+  
/* R:AA,^Z  
**SiteInfoBean.java 1>Dl\czn  
*/ 5"]~oPK  
package NetFox; P"?FnTbv[  
7Wa?$6d  
pge++Di  
public class SiteInfoBean { ?@t  d  
pD2<fP_  
,7)C"  
private String sSiteURL; //Site's URL RQB]/D\BO  
private String sFilePath; //Saved File's Path Gqcz< =/  
private String sFileName; //Saved File's Name L9ap(  
private int nSplitter; //Count of Splited Downloading File zT|)uP*  
9cx =@  
o/ mF #  
public SiteInfoBean() :BukUket1e  
{//nSplitter的缺省值为5 he-Ji  
//default value of nSplitter is 5 + "}=d3E6  
this("","","",5); q4$+H{xB  
} F3lw@b3])  
GK}'R=   
!W'Ui 9uX  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~!d/8?!   
{ y}K\%;`[a  
sSiteURL= sURL; s(LT  
sFilePath = sPath; ~i_Tw#}  
sFileName = sName;  6vTo*8D  
this.nSplitter = nSpiltter; ,prF6*g+WE  
0\~Z5k`IT  
q )lnS )  
} FvuGup`w  
$1zvgep  
4E[!,zvl  
public String getSSiteURL() LrV{j?2@  
{ mNAY%Wn6k  
return sSiteURL; 1b>C<\  
} #4h+j%y[H  
p|/j4@-h  
NHgjRP z"  
public void setSSiteURL(String value) n*'<uKpM  
{ dj&}Gedy  
sSiteURL = value; ZC 4*{  
} iH2n.M "  
m&0"<V!H/B  
"SoHt]%#  
public String getSFilePath() 5ZPzPUa8~  
{ Q2%QLM:.,  
return sFilePath; ^t*x*m8  
} !lmWb-v%36  
qxJQPz  
9H]Lpi^OH  
public void setSFilePath(String value) b2&V  
{ h2;z 4  
sFilePath = value; Dli^2hD  
} Ld,5iBiO:  
B 2 .q3T  
;#) mLsl  
public String getSFileName() JH]K/sC>  
{ s& {Qdf  
return sFileName; Lj %{y.Rj  
} q 'a  
"?GebA  
ZDYJhJ.  
public void setSFileName(String value) Zz |MIGHm  
{ 0ZPV' `KGp  
sFileName = value; 9kY[j2,+  
} X7|.T0{=x  
.2\0~x""  
4oXbPr>  
public int getNSplitter() TE-;X,gDV_  
{ ) I@L+  
return nSplitter; $H'X V"<o  
} %YlTF\-  
MY nH2w]  
@gBE{)Fj  
public void setNSplitter(int nCount) "x&C5l}n  
{ z&3]%t `C  
nSplitter = nCount; 1(GHCxA8G  
} ^yKY'>T#d  
} y9;#1:ic  
qJT0Y/l:(  
]&i+!$N_  
/* 7TX,T|>9  
**Utility.java VLg EX4  
*/ *Wb=WM-.  
package NetFox; )yb+M ez  
SHqyvF  
6=PiVwI  
public class Utility { I7\ &Z q  
&,-p',\-  
#G,XDW2"w  
public Utility() xwzT#DXGJ  
{ Rh] P8  
I(n* _bFq  
re,.@${H  
} a%J6f$A#  
vU/ D7  
//线程睡眠 FX,$_:f6Y  
public static void sleep(int nSecond) _8h8Wtif  
{ bn 4 &O  
try{ 8]0:1 {@  
Thread.sleep(nSecond); -Ubj6 t_K  
} '3kcD7  
catch(Exception e) MdhT!?  
{ R/<=mZ  
e.printStackTrace (); $)e:8jS=  
}  td(M#a-  
} VKLU0*2R  
~j,TVY  
//日志 BSp$F WvT?  
public static void log(String sMsg) Q)Dwq?  
{ +~|AT+|iI  
System.err.println(sMsg); 1}`LTPW9  
} abY0)t  
cvAtwQ'  
}w!ps{*  
public static void log(int sMsg) ":d*dl  
{ jgvh[@uB?  
System.err.println(sMsg); uJ'9R`E ]1  
} A1,4kqmE  
} B$`lY DqaG  
gf$HuCh|  
-%uy63LbHF  
/* 5&4F,v[zp  
**TestMethod.java qZ G-Lh  
*/ 4&}\BU*  
package NetFox; dB|Te"6  
u2`xC4>c  
8g5V,3_6  
public class TestMethod { gB CC  
.Y/-8H-3v  
m(3);)d  
public TestMethod() 4IGxI7~27#  
{ ///xx/weblogic60b2_win.exe T=? bdIl  
try{ .{N\<01  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )Ul&1UYA  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lfMH1llx  
SiteFileFetch fileFetch = new SiteFileFetch(bean); .g-3e"@  
fileFetch.start(); {u]CHN`%Z  
} TSyzdnMvz  
catch(Exception e){e.printStackTrace ();} o#d$[oa  
8)Tj H'  
WX*cICb5  
} mvf _@2^  
hrlCKL&  
O~Uw&Bq  
public static void main(String[] args) VA]ZR+m  
{ @bQ!zCI  
new TestMethod(); k`IrZHMw  
} E2yz=7sv5  
} G(i\'#5+  
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