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http断点续传简单实现(java)

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/* 3+MB5 T  
**SiteFileFetch.java ujW1+Oj=~  
*/ h72UwJ2rw  
package NetFox; 4VN aq<8  
import java.io.*; Z?i /r5F  
import java.net.*; }aB#z<B6  
#s5 pz8v  
KsAH]2Q%  
public class SiteFileFetch extends Thread { F=G{)*Ih  
j:5%ppIY  
,1Qd\8N9  
SiteInfoBean siteInfoBean = null; //文件信息Bean 31Cq22"  
long[] nStartPos; //开始位置 m9M FwfZ  
long[] nEndPos; //结束位置 jc_\'Gr+[  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 X fz`^x>M  
long nFileLength; //文件长度 E04l|   
boolean bFirst = true; //是否第一次取文件 ^=cXo<6D  
boolean bStop = false; //停止标志 mN0=i(H<  
File tmpFile; //文件下载的临时信息 b M;`s5d  
DataOutputStream output; //输出到文件的输出流 vUQFQ  
7J>Gd  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) eX&Gw{U-f  
public SiteFileFetch(SiteInfoBean bean) throws IOException ~E4"}n[3A#  
{ oN[Th  
siteInfoBean = bean; b hjZ7=  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); "$p#&W69"J  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); H;<!TX.zD  
if(tmpFile.exists ()) HU B|bKy  
{ TOl}U  
bFirst = false; YHxbDf dA  
read_nPos(); x )5V.q  
} j{#Wn !,  
else dOa!htx]  
{ S_J :&9L  
nStartPos = new long[bean.getNSplitter()]; '(@YK4_M  
nEndPos = new long[bean.getNSplitter()]; 5/ecaAB2  
} h -_&MD/J  
(J:dK=O@Z  
-237Lx$/  
$%2_{m_K:p  
} bv?0.{Z  
OVoO6F ]  
L^9HH)Jc  
public void run() k/Mp6<?C:  
{ ~M ?|Vn  
//获得文件长度 O^{1RV3:,T  
//分割文件 t7#lsd`_  
//实例FileSplitterFetch WbjF]b\  
//启动FileSplitterFetch线程 #/J 'P[z  
//等待子线程返回 upn8n vy4(  
try{ {sN"( H4$  
if(bFirst) ~JZ3a0$^  
{ l_FGZ!7  
nFileLength = getFileSize();  SVP:D3)  
if(nFileLength == -1) \Z5 +$Ij  
{ )&NAs  
System.err.println("File Length is not known!"); NlR"$  
} :x>T}C<Y  
else if(nFileLength == -2) ka7uK][  
{ e]W0xC-  
System.err.println("File is not access!"); C77D{@SM  
} u'9gVU B  
else dK?); *w]  
{ &TN2 HZ-bJ  
for(int i=0;i<nStartPos.length;i++) B5=3r1Ly  
{ N} />rD  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 8q_0,>w%  
} 1/j$I~B   
for(int i=0;i<nEndPos.length-1;i++) euRss#;  
{ Z-Wfcnk  
nEndPos = nStartPos[i+1]; :Am-8  
} a4GWuozl  
nEndPos[nEndPos.length-1] = nFileLength; dBEIMn@  
} MB$a82bY  
} a#(U2OP  
vgPUIxB@  
D(Ix!G/  
//启动子线程 !c8L[/L  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /J%do]PDl  
for(int i=0;i<nStartPos.length;i++) 2YQ#-M  
{ &{^eU5  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XDmbm*~i  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P[gO85  
nStartPos,nEndPos,i); v+q<BYq  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hYt7kq!"  
fileSplitterFetch.start(); >S&U.  
} wz#[:2  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TL-i=\{L:d  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }0eg{{g8  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oj.lj!  
nEndPos = " + nFileLength); )5l u.R%  
// fileSplitterFetch[nPos.length-1].start(); ~@M7&%]  
k&Jo"[i&WO  
A!HK~yk~Q  
//等待子线程结束 04-Z vp2  
//int count = 0; 9`X&,S~e  
//是否结束while循环 N=fz/CD)I  
boolean breakWhile = false;  ]6~k4  
W7e4pR?w  
Y}1 P~  
while(!bStop) XL"=vbD  
{ v&0d$@6/U  
write_nPos(); |^5/(16  
Utility.sleep(500); az(5o  
breakWhile = true; i.@*t IK  
qzdaN5  
c cr" ep  
for(int i=0;i<nStartPos.length;i++) 3"i% {  
{ qpgU8f  
if(!fileSplitterFetch.bDownOver) _Xh=&(/8@  
{ sco uO$K  
breakWhile = false; "Gh#`T0#a  
break; )+GX<2_  
} ,VG9)K 1K  
} zzJ^x8#R  
if(breakWhile) f)gGH'yOQ  
break; 6o lV+  
*,jqE9:O  
)1z4q`  
//count++; O)<r>vqe}  
//if(count>4) @ R'E?|  
// siteStop(); ) hdgz$cl  
} m!!;/e?yx  
gE=Wcb!  
&t[|%c*D&  
System.err.println("文件下载结束!"); gH H&IzHF  
} TNsg pJ?\  
catch(Exception e){e.printStackTrace ();} vl~%o@*_  
} HWbBChDF  
GMb!Q0I8  
W:B}u\)C  
//获得文件长度 u[[/w&UV.,  
public long getFileSize() (-2R{! A  
{ !u0U5>ccw  
int nFileLength = -1; .CmL7 5  
try{ #_p  
URL url = new URL(siteInfoBean.getSSiteURL()); oP-;y&AS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7K !GK  
httpConnection.setRequestProperty("User-Agent","NetFox"); lm &^tjx  
+3?`M<L0  
ScHlfk p  
int responseCode=httpConnection.getResponseCode(); onh?/3l  
if(responseCode>=400) 2mOfsn d@  
{ AO8:|?3S  
processErrorCode(responseCode); T g\hx>  
return -2; //-2 represent access is error P%jkKE?B4  
} [Y oa"K  
wz@/5c/u  
+9~ZA3DiP  
String sHeader; !h/dZ`#  
% &+|==-  
z@n+7p`w  
for(int i=1;;i++) Sgx+V"bkT  
{ e@+v9Bs]q  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ei~]iZ}  
//Utility.log(in.readLine()); yUj;4vd  
sHeader=httpConnection.getHeaderFieldKey(i); y3AL)  
if(sHeader!=null) :+1bg&wQ  
{ 3Pa3f >}-  
if(sHeader.equals("Content-Length")) ])68wqD  
{ 9dw0<qw1%  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?:JdRnH\  
break; jqqaw  
} jQ^Yj"6  
} {Ot[WF  
else KMe.i'  
break; 5 2fO)!  
} Nq  U9/  
} ndB@J*Imu  
catch(IOException e){e.printStackTrace ();} S#hu2\9D,  
catch(Exception e){e.printStackTrace ();} &}O8w77  
SE-} XI\  
{'&8`d  
Utility.log(nFileLength); _32/WQF6  
o:f|zf> i<  
jiOf')d5  
return nFileLength; u4C1W|x  
} <JJkki  
l [x%I  
&LwJ'h +nd  
//保存下载信息(文件指针位置) P$ F#,Cn  
private void write_nPos() iF+S%aPd#  
{ k~ZBJ+ 94  
try{ dvxf lLd @  
output = new DataOutputStream(new FileOutputStream(tmpFile)); p0?o<AA%O  
output.writeInt(nStartPos.length); >Ziy1Dp  
for(int i=0;i<nStartPos.length;i++) 6J]~A0vsi}  
{ 89ZDOji?O  
// output.writeLong(nPos); i"KL;t[1  
output.writeLong(fileSplitterFetch.nStartPos); e ^-3etx  
output.writeLong(fileSplitterFetch.nEndPos); ul}4p{ m[  
} vN' VDvVM  
output.close(); tvK rc  
} J1& A,Gb  
catch(IOException e){e.printStackTrace ();} kS[Dy$AB/2  
catch(Exception e){e.printStackTrace ();} ;q'DGzh  
} y K=S!7p\  
C!`>cUhE{  
c;nx59w ]q  
//读取保存的下载信息(文件指针位置) &boj$ k!g[  
private void read_nPos() i<0D Z_rub  
{ v5P*<U Ax  
try{ /1H9z`qV  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PlF89-  
int nCount = input.readInt(); *C tsFS~  
nStartPos = new long[nCount]; |:\$n}K  
nEndPos = new long[nCount]; tc!!W9{69  
for(int i=0;i<nStartPos.length;i++) 54;l*}8Hl  
{ t.gq5Y.[  
nStartPos = input.readLong(); Cbazwq  
nEndPos = input.readLong(); eR(\s_`  
} #I bS  
input.close(); m`[oT\  
} cYE./1D a  
catch(IOException e){e.printStackTrace ();} C8! 8u?k  
catch(Exception e){e.printStackTrace ();} f&+XPd %  
} k{zs578h2  
7=; D0SS  
0@JilGk1u  
private void processErrorCode(int nErrorCode) q+r ` e  
{ ~r{\WZ.  
System.err.println("Error Code : " + nErrorCode); J~M H_N  
} G*8+h  
C+ZQB)gn  
'nC3:U  
//停止文件下载 A!Knp=Gw  
public void siteStop() TB ;3`  
{ >SY 2LmV'a  
bStop = true; hwEZj`9  
for(int i=0;i<nStartPos.length;i++) 1kbT@  
fileSplitterFetch.splitterStop(); f%`*ba" v  
\Ac}R'  
TW'E99wG  
} e4[-rkn{hl  
} {d&X/tT  
//负责部分文件的抓取 )er?*^9Z  
**FileSplitterFetch.java nNd`]F^U  
*/ j;$6F/g  
package NetFox; +9Xu"OFm  
ey'pm\Z  
OHx,*}N  
import java.io.*; /&S~+~]n  
import java.net.*; fho=<|-  
} IIK~d,  
|iLx $P6  
public class FileSplitterFetch extends Thread {  muK'h`  
61ON  
c+}!yH$  
String sURL; //File URL R4z<Xf:!  
long nStartPos; //File Snippet Start Position 94Kuy@0:+  
long nEndPos; //File Snippet End Position Z%,\+tRe  
int nThreadID; //Thread's ID 6\NX 5Gh  
boolean bDownOver = false; //Downing is over JL}hOBqfI  
boolean bStop = false; //Stop identical {mCKTyN+  
FileAccessI fileAccessI = null; //File Access interface +#de8/x  
~0' _K1(H  
zgEr,nF  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uW\@x4  
{ GoGohsj  
this.sURL = sURL; h(+m<J  
this.nStartPos = nStart; ~`nm<   
this.nEndPos = nEnd; =;'ope(?S  
nThreadID = id; tdMP,0u  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,yB?~  
} xI.Orpw  
4?P%M"\Iv  
CF4Oh-f  
public void run() i?1js! 8  
{ 4Zv.[V]iOO  
while(nStartPos < nEndPos && !bStop) kxr6sO~  
{ =8$(i[;6w  
^P3g9'WK  
.(P@Bl]XJ  
try{ .!7Fe)(x  
URL url = new URL(sURL); $M}k%Z  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X]3l| D  
httpConnection.setRequestProperty("User-Agent","NetFox"); =hZ&66  
String sProperty = "bytes="+nStartPos+"-"; ft~|  
httpConnection.setRequestProperty("RANGE",sProperty); al3BWRq'f  
Utility.log(sProperty); +SZ%&  
}"g21-T^  
l`~a}y"n  
InputStream input = httpConnection.getInputStream(); Z>>gXh<e[  
//logResponseHead(httpConnection); ?9wFV/  
! 4qps$p{  
p[af[!  
byte[] b = new byte[1024]; $ DABR  
int nRead; q:EzKrE  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !_^ {udB}  
{ v;N1'  
nStartPos += fileAccessI.write(b,0,nRead); '0])7jq  
//if(nThreadID == 1) Q5`+eQ?_\  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eCPKpVhP  
} !R] CmK  
Kd ryl   
lzr>WbM{{p  
Utility.log("Thread " + nThreadID + " is over!"); :$GL.n-?  
bDownOver = true; m-Z'K_oQ  
//nPos = fileAccessI.write (b,0,nRead); c1)BGy li  
} OTNZ!U/)j  
catch(Exception e){e.printStackTrace ();} 9" }^SI8  
} LoV*YSDAY  
} ,\m;DR1  
[+:mt</HN  
3;t@KuQ66  
//打印回应的头信息 ^cPo{xf  
public void logResponseHead(HttpURLConnection con) F=*BvI "+  
{ r+V(1<`2X  
for(int i=1;;i++) ?}1JL6mF{  
{ l?yZtZ8  
String header=con.getHeaderFieldKey(i); EE{#S  
if(header!=null) Mi %1+  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mhJOR'2  
Utility.log(header+" : "+con.getHeaderField(header)); k?|F0e_  
else n8;G,[GM80  
break; L8?Z!0D/h  
} w/^0tZ~  
} SS45<!i y  
Fb\2df{@  
sa0^1$(<  
public void splitterStop() Rrs`h `'-  
{ =JySY@?9  
bStop = true; /RXk[m-  
} om*tdG  
]Nd'%M  
tx|"v|&e2  
} mAYr<=  
X"qbB4 (I  
!5' 8a5  
/* I ")"s  
**FileAccess.java -; /@;W  
*//文件访问(定位,写) kw-Kx4 )  
package NetFox; ]~g|SqPA@  
import java.io.*; =aCIaL&9Y  
9bzYADLI  
+hKPOFa'  
public class FileAccessI implements Serializable{ L2/<+ Zw  
[r~rIb%Zj  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节  \3y=0  
RandomAccessFile oSavedFile; #`6OC)1J  
long nPos; HS5Ug'\446  
WKYA9BaR  
|+4E 8;4_  
public FileAccessI() throws IOException 31o7R &v  
{ [}xIg8  
this("",0); 9>$%F;JP44  
} |qudJucV  
\A~I>x  
|"tV["a  
public FileAccessI(String sName,long nPos) throws IOException 6!}m$Dvt~  
{ A0N ;VYv  
oSavedFile = new RandomAccessFile(sName,"rw"); ~_l: b  
this.nPos = nPos; BGh8\2  
oSavedFile.seek(nPos); WX[dM }L  
} 1WA""yb  
)>#<S0>'j  
RAx]Sp Q-S  
public synchronized int write(byte[] b,int nStart,int nLen) r^o}Y  
{ \Dsl7 s=  
int n = -1; i]^*J1a  
try{ :R|2z`b!  
oSavedFile.write(b,nStart,nLen); r<f-v_bxF  
n = nLen; I +4qu|0lA  
} *i]Z=  
catch(IOException e) E/ed0'|m  
{ XGrxzO|{  
e.printStackTrace (); Z]>e& N  
} \8>N<B)  
FUTyx"   
hwol7B>   
return n; ?[>BssW  
} :#!F 7u  
A&_i]o  
*}WqYqOow  
} ?$8 ,j+&I  
K?9H.#(  
$m%/veD k  
/* G}hkr  
**SiteInfoBean.java B8#f^}8  
*/ "F.J>QBd  
package NetFox; O 9 Au =  
;uo|4?E:\(  
$}h_EI6hS  
public class SiteInfoBean { qpEC!~ y  
8'_ ]gfF  
$MVeMgPa  
private String sSiteURL; //Site's URL W!9f'Yn  
private String sFilePath; //Saved File's Path RV@(&eM  
private String sFileName; //Saved File's Name  D]>86&  
private int nSplitter; //Count of Splited Downloading File T6?d`i i1  
93p9?4;n-  
RkXLE"G '  
public SiteInfoBean() 'w$we6f  
{//nSplitter的缺省值为5 +z/73s0~  
//default value of nSplitter is 5 HBkQ`T  
this("","","",5); *q 9$SDm  
} )d a8 Ru  
!m.')\4<  
).#D:eO[~  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %;XuA*e  
{ ;og<eK  
sSiteURL= sURL; n#AH@`&i  
sFilePath = sPath; / z>8XM&  
sFileName = sName; rO >wX_  
this.nSplitter = nSpiltter; |`9zE]  
a{YVz\?d}  
I)4|?tb ?  
} p.7p,CyB  
RPqn#B  
ZFw743G  
public String getSSiteURL() @[ N~;>  
{ -Y,Ibq  
return sSiteURL; 4'eVFu+62  
} 9 u89P  
k5\ zGsol  
@ShJ:  
public void setSSiteURL(String value) j{+I~|ZB,  
{ H ;}ue  
sSiteURL = value; C2%3+  
} *m Tc4&*  
Xpz-@fqKdf  
.TU15AAc  
public String getSFilePath() @?NLME  
{ NNV.x7  
return sFilePath; 24k}~"We  
} p+1B6j  
N9hWx()v  
sSb&r  
public void setSFilePath(String value) g}`CdVQ2M<  
{ R1%T>2"~&  
sFilePath = value; !f[N&se  
} 3JO:n6  
\DdVMn  
?4dd|n  
public String getSFileName() &%51jM<  
{ A)0m~+?{J  
return sFileName; G`K7P`m  
} KUV{]?'  
,tc]E45  
obkv ]~  
public void setSFileName(String value) a'.=.eDQ  
{ }{PtQc6RL!  
sFileName = value; ~oyPmIcb  
} W| eG}`  
Hd}t=6  
^8t*WphZC  
public int getNSplitter() K_Gf\x  
{ @y%qQe/g  
return nSplitter; Gs?sO?j  
} Xc<9[@  
Cf 8 - %  
{i?K~| h  
public void setNSplitter(int nCount) a.Vs >1  
{ ITOGD  
nSplitter = nCount; P=i |{vv(  
} l)eaIOyk  
} 2Nszxvq,  
K1yM'6 Zw  
xpo}YF'5  
/* v<4X;4p^  
**Utility.java jtJU 5Q  
*/ O~1p]j  
package NetFox; FiH!) 6T  
S!c@6&XJm?  
@ uWD>(D  
public class Utility { U;Wmx  
7E]l=Z`x  
p#I1l2nE  
public Utility() }e6:&`a xD  
{ 3@A k6Uh  
s;)tLJ!  
;<Q_4 V  
} @J)vuGS  
7tnzgtal  
//线程睡眠 `fHiY.-  
public static void sleep(int nSecond) :"^$7  
{  HuC lO  
try{ Y`RfE  
Thread.sleep(nSecond); F:U_gW?  
} Gj0NN:  
catch(Exception e) cZ,_O~  
{ z[Qv}pv  
e.printStackTrace (); Z/;SR""wa  
} O`| ri5d  
} Q?q m~wD  
m]vr|:{6/  
//日志 Sy~Mh]{E  
public static void log(String sMsg) IT"jtV  
{ {hR23eE)#  
System.err.println(sMsg); \/G Y0s  
} HyMb-Us  
sJvn#cS  
`_ L|I s=n  
public static void log(int sMsg) 7u(i4O& k  
{ &ICO{#v5  
System.err.println(sMsg); lD XH<W?  
} 8hY)r~!b'  
} G 0 yt%qHE  
q5Mif\  
1jb@n xRjO  
/* f# + h_1#  
**TestMethod.java /+7L`KPD  
*/ _69\#YvCG  
package NetFox; i vk|-C'\  
=Ch#pLmH  
YWdvL3Bgk,  
public class TestMethod { _X/`4 G  
CSs6Vm!=  
:4TcCWG  
public TestMethod() t~M_NEPxV  
{ ///xx/weblogic60b2_win.exe $P~a   
try{ NI)nf;C  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W525:h52{  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Wov_jVdN\  
SiteFileFetch fileFetch = new SiteFileFetch(bean); +d96Z^KUhv  
fileFetch.start(); cm<3'#~Q?  
} b"V-!.02  
catch(Exception e){e.printStackTrace ();} dWSH\wm+  
.BvV[`P  
IU}`5+:m  
} :|TBsd|/x  
$+j )  
a{=~#u8  
public static void main(String[] args) 6]*qx5m`<l  
{ }"v "^5  
new TestMethod(); >XN&Q VE  
} j3U8@tuG  
} x$*OglaS  
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