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http断点续传简单实现(java)

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/* _'Rzu'$`  
**SiteFileFetch.java ckhU@C|=*  
*/ E 8LA+dKN:  
package NetFox; F(}~~EtPHo  
import java.io.*; ;:DDz  
import java.net.*; RJhafUJ zH  
OPe3p {]  
h}$g}f%$+  
public class SiteFileFetch extends Thread { :)=>,XwL8  
RM|2PG1m  
l>){cI/D#  
SiteInfoBean siteInfoBean = null; //文件信息Bean R q |,@  
long[] nStartPos; //开始位置 fWk,k*Z 9  
long[] nEndPos; //结束位置 ta+MH,  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 :XFr"aSt  
long nFileLength; //文件长度 XV %DhR=  
boolean bFirst = true; //是否第一次取文件 |9'`;4W  
boolean bStop = false; //停止标志 kfj)`x  
File tmpFile; //文件下载的临时信息 z}z 6Vg  
DataOutputStream output; //输出到文件的输出流 T0TgV  
($or@lfs  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Vl\8*!OL%  
public SiteFileFetch(SiteInfoBean bean) throws IOException M%(^GdI#Vf  
{ Z`]r)z%f  
siteInfoBean = bean; ms%RNxU4:  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); hteAuz4H  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ' Ih f|;r  
if(tmpFile.exists ()) ='G-wX&k  
{ JG/Pc1aK  
bFirst = false; "&Rt&S  
read_nPos(); 0(|Yy/Yq  
} rHaj~s 4  
else  @ ^cR  
{ CFTw=b@  
nStartPos = new long[bean.getNSplitter()]; oT0TbZu%  
nEndPos = new long[bean.getNSplitter()]; +{h.nqdAE  
} SPN5H;{[]K  
Uu_Es{@  
!YVGT <  
-~] q?k?  
} j/p1/sJ[y  
PX/7:D?  
xNOArb5e5  
public void run() a${<~M hm  
{ RIdh],-  
//获得文件长度 +=MN_  
//分割文件 Mj<T+Ohz  
//实例FileSplitterFetch 67b w[#v  
//启动FileSplitterFetch线程 Q5xQ5Le  
//等待子线程返回  PrqyJ  
try{ |5TzRz  
if(bFirst) NpLZ ,|H  
{ H ]z83:Z  
nFileLength = getFileSize(); "K c/Cs2[  
if(nFileLength == -1) 3ZUME\U  
{ iz%wozf  
System.err.println("File Length is not known!"); B? Z_~Bf&  
} E< Y!BT[X  
else if(nFileLength == -2) U[EZ, 7n8  
{ ? FlQ\q  
System.err.println("File is not access!"); %urd;h D  
} x:$ xtu  
else V jLv{f<p  
{ MSaOFv_Q  
for(int i=0;i<nStartPos.length;i++) [nASMKK0  
{ m gE r+  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); c> 0R_  
} 3 63KU@`  
for(int i=0;i<nEndPos.length-1;i++) z50P* eS  
{ ZA+w7S3  
nEndPos = nStartPos[i+1]; ^).  
} K1$   
nEndPos[nEndPos.length-1] = nFileLength; F}~qTF;H  
} Bwl@Muw  
} '\M]$`Et  
5=_bK^Am  
hQ ?zc_ 3  
//启动子线程 fSF_O}kLp  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cDIZkni=  
for(int i=0;i<nStartPos.length;i++) %#x l+^  
{ bRD-[)  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )uu(I5St  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ge7Uety  
nStartPos,nEndPos,i); Nsn~mY%  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H <9_BA?  
fileSplitterFetch.start(); H~ E<ek'~  
} %<0'xJ%%Q  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z`<5SHQd  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); bH.SUd)  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UZpQ%~/  
nEndPos = " + nFileLength); 3 <)+)n  
// fileSplitterFetch[nPos.length-1].start(); Z 4QL&?U  
/>n!2'!  
`a `>Mtl  
//等待子线程结束 \`;1[m  
//int count = 0; ;,/4Ry22j-  
//是否结束while循环 "H#pN;)+   
boolean breakWhile = false; 5.$/]2VK  
-}u1ZEND  
" GY3sam  
while(!bStop) xz Hb+1+p  
{ [/o B jiBA  
write_nPos(); z HT#bP:o  
Utility.sleep(500); #/> a`Ur_  
breakWhile = true; Z!-V&H.  
d$^ @$E2f  
y* :C~  
for(int i=0;i<nStartPos.length;i++) V|G*9^Y  
{ UD=[::##  
if(!fileSplitterFetch.bDownOver) qP0UcG  
{ D"gv:RojD  
breakWhile = false; C8W_f( i~  
break; OS-k_l L  
} NvC @  
} $zM \Jd  
if(breakWhile) =~k}XB  
break; #(QS5J&Qq  
0t[ 1#!=k  
pg Q^w0BQV  
//count++; /dO*t4$@?  
//if(count>4) @/,0()*dL  
// siteStop(); .W\JvPTC  
} +%H=+fJ2}  
&NOCRabc  
@?>5~  
System.err.println("文件下载结束!"); eA*We  
} z\"9T?zoo  
catch(Exception e){e.printStackTrace ();} k t'[  
} fZoQQ[s  
:k-@w5(  
PhAD: A  
//获得文件长度 \l%##7DRp]  
public long getFileSize() a6@k*9D>  
{ |8tKN"QG  
int nFileLength = -1; Po&'#TC1  
try{ # [ +n(  
URL url = new URL(siteInfoBean.getSSiteURL()); pedyWA>  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T"t.t%(8  
httpConnection.setRequestProperty("User-Agent","NetFox"); qI>,PX  
yuC|_nL  
&dPUd ~&EL  
int responseCode=httpConnection.getResponseCode(); Yxy!&hPLv:  
if(responseCode>=400) - (7oFOtg  
{ m%'T90mi  
processErrorCode(responseCode); F"cZ$TL]  
return -2; //-2 represent access is error 3xN_z?Rg  
} gF`hlYD  
Xvk+1:D  
~^'WHuz Py  
String sHeader; #l h' !  
M N (o  
6VS_L@  
for(int i=1;;i++) LcT;7yv  
{ F|cli <  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1/,~0N9  
//Utility.log(in.readLine()); L)8%*X  
sHeader=httpConnection.getHeaderFieldKey(i); 65nK1W`i  
if(sHeader!=null) g6+5uvpd  
{ E62_k 0q  
if(sHeader.equals("Content-Length")) Ls+vWfF=#  
{ Rn`DUYg  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9R">l5u  
break; 8 &v)Vi-  
} &O#1*y Z  
} 7kITssVHI  
else ~T/tk?:8Vi  
break; P,b&F  
} cltx(C>   
} qA[cF$CIl)  
catch(IOException e){e.printStackTrace ();} mN> (n+ly  
catch(Exception e){e.printStackTrace ();} Q+/P>5O/  
: sw@1  
z`eMb  
Utility.log(nFileLength); :Gzp (@<@e  
f]mVM(XZN  
?o`:V|<v  
return nFileLength; R](cko=  
} =Ot_P7'5gv  
Gx4{ 9  
4'tY1 d  
//保存下载信息(文件指针位置) ]omBq<ox'Y  
private void write_nPos() HGDiwA  
{ G*,7pc  
try{ XL9-N?(@  
output = new DataOutputStream(new FileOutputStream(tmpFile)); fQwLx  
output.writeInt(nStartPos.length); t BG 9Mn  
for(int i=0;i<nStartPos.length;i++) .;S1HOHz4  
{ d^v.tYM$N  
// output.writeLong(nPos); [>U2!4=$M  
output.writeLong(fileSplitterFetch.nStartPos); p$ETAvD  
output.writeLong(fileSplitterFetch.nEndPos); j/F('r~L  
} 2kk; z0f  
output.close(); A`Rs n\  
} -%Ce  
catch(IOException e){e.printStackTrace ();} =d iGuI B  
catch(Exception e){e.printStackTrace ();} |f\WVGH  
} 4?+jvVq  
~3&hvm[IQ  
OT$++cj^  
//读取保存的下载信息(文件指针位置) \KS.A 4  
private void read_nPos() ^.  
{ $pt~?ZZ3-  
try{ mB6%. "  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Gd'_X D  
int nCount = input.readInt(); K r<UPr  
nStartPos = new long[nCount]; us8HXvvp{  
nEndPos = new long[nCount]; E$ &bl  
for(int i=0;i<nStartPos.length;i++) +WKN&@  
{ r:Q=6j,  
nStartPos = input.readLong(); 3.g4X?=zd  
nEndPos = input.readLong(); V#+F*w?&D  
} VS!v7-_N5  
input.close(); yW\kmv.O  
} _3NH"o d  
catch(IOException e){e.printStackTrace ();} _y sakn  
catch(Exception e){e.printStackTrace ();} !qHB?]  
} `Q/\w1-Q  
7Ka4?@bQ  
ori[[~OyB  
private void processErrorCode(int nErrorCode) FQE(qltf,  
{ cct/mX2&~  
System.err.println("Error Code : " + nErrorCode); P}>>$$b\Yi  
} Ab:ah 7!  
,rF!o_7  
G:wO1f6  
//停止文件下载 B2KBJ4rI[1  
public void siteStop() 1C]BaPbL  
{  p: eaZ  
bStop = true; #/8 Na v  
for(int i=0;i<nStartPos.length;i++) `B:hXeI  
fileSplitterFetch.splitterStop(); 1_]%,  
TJ>1?W\Z  
baL<|& c  
} GXNkl?#  
} Y^U^yh_!^  
//负责部分文件的抓取 |5&7;;$  
**FileSplitterFetch.java #yU"n-eLR  
*/ %o0H#7'  
package NetFox; la4%Vqwgu  
 c,M"a  
( z F_<  
import java.io.*; 0I do_V  
import java.net.*; [-81s!#mkw  
W^S]"N0u  
VR A+p?7-  
public class FileSplitterFetch extends Thread { )K`tnb.Pf  
Pj_DI)^  
q_L. Sy|)  
String sURL; //File URL !R#PJH/TM  
long nStartPos; //File Snippet Start Position QFoCi&  
long nEndPos; //File Snippet End Position tA'5ufj*:  
int nThreadID; //Thread's ID .I$+ E  
boolean bDownOver = false; //Downing is over Q`4I a<5B  
boolean bStop = false; //Stop identical }W[=O:p  
FileAccessI fileAccessI = null; //File Access interface a<>cbP  
l<ZHS'-;8  
2R^Eea  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s8qpK; O  
{ Fpwhyls  
this.sURL = sURL; Z!jJ93A"  
this.nStartPos = nStart; Ke]'RfO\  
this.nEndPos = nEnd; ,^<39ng  
nThreadID = id; %K06owV(S)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +Jn\`4/J:  
} >IA1 \?(  
@+)T"5_Y[  
Y?zo")  
public void run() u6IM~kk>5  
{ a40>_;}:x  
while(nStartPos < nEndPos && !bStop) sJl>evw  
{ Z:V<P,N  
|z&7KoYK'  
ER@RWV 2  
try{ :S!!J*0  
URL url = new URL(sURL); HCe/!2Y/%  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >Rb jdM5K4  
httpConnection.setRequestProperty("User-Agent","NetFox"); UlKg2p  
String sProperty = "bytes="+nStartPos+"-"; l|vT[X/g  
httpConnection.setRequestProperty("RANGE",sProperty); SJi;_bVf  
Utility.log(sProperty); 8]O#L}"  
d>c`hQ(V  
[a}Idi` K  
InputStream input = httpConnection.getInputStream(); 8YgRJQZ!  
//logResponseHead(httpConnection); 78<fbN5}r  
oz[G'[\}F  
=}u?1~V  
byte[] b = new byte[1024]; i .eMrzJ|  
int nRead; y&\t72C$Fi  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) sb1tQ=u[  
{ npbf>n^R  
nStartPos += fileAccessI.write(b,0,nRead); ~DB:/VSmu  
//if(nThreadID == 1) J~ +p7S  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fD8GAav  
} k)y<iHR_o  
A1z<2.R  
Y$j !-l5z  
Utility.log("Thread " + nThreadID + " is over!"); [ :Sl~  
bDownOver = true; [D<(xr&N%  
//nPos = fileAccessI.write (b,0,nRead); 8,VEuBZ  
} =)N6 R  
catch(Exception e){e.printStackTrace ();} / T_v8 {D  
} O`N,aYo  
} O#>,vf$  
:!fY;c?  
}*aj&  
//打印回应的头信息 G Uh<AG*+  
public void logResponseHead(HttpURLConnection con) V%C'@m(/SZ  
{ ~3-+~y=o~  
for(int i=1;;i++) ?[WUix;  
{ -yu$Mm  
String header=con.getHeaderFieldKey(i); s&wm^R  
if(header!=null) 3Q)"  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \8vZZt  
Utility.log(header+" : "+con.getHeaderField(header)); M9(lxu y1  
else "+ k}#<P4\  
break; fi&>;0?7  
} i1]}Q$  
} 1-.i^Hal  
7qWa>fX  
/#L4ec-'  
public void splitterStop() %rEP.T\i  
{ 9VIAOky-  
bStop = true; 2Qc_TgWF  
} 3RcnoXX_  
Z*v`kl  
}>3jHWxLc  
} at2)%V)  
_. EM])b  
pE0@m-p  
/* E>2AG3)  
**FileAccess.java e ]2GAJLI  
*//文件访问(定位,写) Z7?\ >4V  
package NetFox; %j{*`}  
import java.io.*; rTJ;s  
') 2LP;(  
89P7iSV#*  
public class FileAccessI implements Serializable{ NpbZt;%t  
fl4'dv  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R4zOiBi'B  
RandomAccessFile oSavedFile; Z]5xy_La  
long nPos; `>lY$EBG@[  
wNNg"}&P  
77]lp mC  
public FileAccessI() throws IOException tZ*>S]qD  
{ 8k.#4}fP  
this("",0); kn`O3cW/  
} #&z'?x^a  
)2u_c=  
R[m+s=+  
public FileAccessI(String sName,long nPos) throws IOException 9PaV*S(\TR  
{ %.fwNS  
oSavedFile = new RandomAccessFile(sName,"rw"); 5*Dh#FRp  
this.nPos = nPos; 5CH8;sMK  
oSavedFile.seek(nPos); bZj5qjl`x  
} y"K[#&,0  
yD0DPtti  
'c >^Aai  
public synchronized int write(byte[] b,int nStart,int nLen) zqRps8=  
{ o+- 0`!yj  
int n = -1; |f$gQI!XW  
try{ ]9w TAb  
oSavedFile.write(b,nStart,nLen); ogV v 8Xb  
n = nLen; |F qujZz  
} ?d k)2  
catch(IOException e) ,WAJ& '^  
{ [EQTrr( D  
e.printStackTrace (); rV*Ri~Vx  
} `?d` #) Ck  
s>{\^T7y  
zOy_qozk  
return n; "K;""]#wg0  
} )L_@l5l  
/U6ry'  
j|[>f  
} vJX0c\e  
e YiqTWn:  
Ypinbej  
/* { / ,?3  
**SiteInfoBean.java )t2eg1a:  
*/ c;n\HYk  
package NetFox; Lg-!,Y   
2cZgG^  
ajf(Ii\/  
public class SiteInfoBean { Pv*]AF;9pQ  
Oz<#s{Z  
"DX 2Mu=  
private String sSiteURL; //Site's URL /38XaKc{6  
private String sFilePath; //Saved File's Path y3P4]sq  
private String sFileName; //Saved File's Name P\@efq@!  
private int nSplitter; //Count of Splited Downloading File jm'^>p,9G  
-"x@V7X  
\J-D@b;  
public SiteInfoBean() <EY{goW  
{//nSplitter的缺省值为5 AMK(-=  
//default value of nSplitter is 5 D23 c/8K  
this("","","",5); g ?@fHFct  
} wb39s^n  
@z=L\ e{  
f$--y|=  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hK %FpGYA  
{ tNYuuC%N  
sSiteURL= sURL; B!4~A{  
sFilePath = sPath; 0E@*&Ru  
sFileName = sName; NuXII-  
this.nSplitter = nSpiltter; &&zsUAkS  
,=: -&~?  
#K/95!)  
} ROO@EQ#`Z  
E+$D$a  
<2N=cH'  
public String getSSiteURL() u $D%Iz  
{ [7,q@>:CS  
return sSiteURL; _auFt"n  
} HzsQ`M4cA  
gIKQip<  
3MDs?qx>s  
public void setSSiteURL(String value) HI[Pf%${  
{ &#!1 Y[e^  
sSiteURL = value; a/[)A _-  
} C>QWV[F  
'k[vcnSz\/  
,G[Y< ~Hy  
public String getSFilePath() a&7uRR26  
{ s|k&@jH)  
return sFilePath; }:!X@C~  
} 3KtJT&RuL  
oFsV0 {x%)  
wVc ^l  
public void setSFilePath(String value) y<c7RK]  
{ 3`Xzp  
sFilePath = value; dq0!.gBT2  
} !.499H3  
!1Ht{cA0  
wEQZ9?\  
public String getSFileName() HumL(S'm  
{ 7"OJ,Mx%  
return sFileName; xl@~K^c]  
} bL5u;iy)  
?. Ip(g  
{vQ:4O!:  
public void setSFileName(String value) BKYyc6iE  
{ fm!\**Q1  
sFileName = value; |OuIQhoE  
} _ER. AKY  
`^|l+TJG  
JoD@e[(  
public int getNSplitter() [$#G|>x  
{ Of}C.N8  
return nSplitter; RrdLh z2N  
} OP\L  
1\g r ;b  
`O`MW} c  
public void setNSplitter(int nCount) )jh~jU?c@  
{ AS'+p%(  
nSplitter = nCount; 8is QL  
} =q*c}8R_0  
} yet ~  
yD@1H(yM  
lbC,*U^  
/* Vlge*4q  
**Utility.java Z*=$n_ G  
*/ X8wtdd]64  
package NetFox; KN>h*eze  
_hMFmI=r[  
}y vH)q  
public class Utility { I+31:#d  
7m}fVLk  
}'K-1:  
public Utility() ,sT5TS q  
{ Y~?Z'uR  
Pz 0TAb  
"=V!-+*@G@  
} U2v;GIo$yU  
A2 $05a$%  
//线程睡眠 <j3|Mh_(I  
public static void sleep(int nSecond) k= &n>P  
{ }7_$[r'_oI  
try{ E()%IC/R  
Thread.sleep(nSecond); 0 ZSn r+  
} U*,\UF  
catch(Exception e) d]MpE9@'v  
{ OL_jU2,fv  
e.printStackTrace (); e3?z^AUXm  
} wuM'M<J@  
} u4bVp+  
qh6rMqq  
//日志 }0iHf'~DH*  
public static void log(String sMsg) Sh?eb  
{ qW'L}x  
System.err.println(sMsg); J~50#vHY  
} y|zIu I-p  
>]o>iOz;]  
Z] x6np  
public static void log(int sMsg) !~V^GlY  
{ h4+*ssnYV  
System.err.println(sMsg); d24_,o\_  
} ;--D?Gs]Qr  
} >(.Y%$9"E  
7 |GSs=  
qw>vu7/z  
/* "h|kf% W  
**TestMethod.java \A)Pcc}7  
*/ A;dD'Kgl  
package NetFox; ZX#60o8  
|o'r?"  
n{&;@mgI  
public class TestMethod { w'E?L`c  
2e03m62*  
p#_ 5w  
public TestMethod() GLX{EG9Z  
{ ///xx/weblogic60b2_win.exe EVC]B}  
try{ M|zTs\1I  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CGkx_E]  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _pDfPLlY&  
SiteFileFetch fileFetch = new SiteFileFetch(bean); U3` ?Z`i(  
fileFetch.start(); Eggu-i(rD  
} Pn6~66a6  
catch(Exception e){e.printStackTrace ();} %(W8W Lz}  
L u'<4 R  
B*w]yL(  
} ),[@NK&=  
`xx3JQv[  
&]shBvzl^  
public static void main(String[] args) Y=g]\%-PB  
{ h=JW^\?\]  
new TestMethod(); >5?:iaq z  
} zqBzataR:  
} \ 9iiS(e  
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