http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); |4-Ey! P
} ]>`Q"g~0
for(int i=0;i<nEndPos.length-1;i++) >:wk.<Z-
{ qtgj"4,:`
nEndPos = nStartPos[i+1]; LW,!B.`@
} dd$\Q
nEndPos[nEndPos.length-1] = nFileLength; wmT3 >
} nC`=quM9
} !5=3Y4bg1
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,Xb:f/lB
//启动子线程 rU'&o) a^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7 H<_ wW
for(int i=0;i<nStartPos.length;i++) cJH7zumM)
{ (cA=~Bw[=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QR^pu.k@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6NZf!7,B
nStartPos,nEndPos,i); &G'R{s&"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =@ON>SmPs
fileSplitterFetch.start(); *4.f*3*
} eH1Y!&`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2gFQHV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J/ rQ42d
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Uvz9x"0[u
nEndPos = " + nFileLength); :!aFfb["
// fileSplitterFetch[nPos.length-1].start(); (1TYJ. Z
^&Qaf:M
{O!fV<Vx 9
//等待子线程结束 Cf%)W:Q9
//int count = 0; L(X:=) !K0
//是否结束while循环 s!UC{)g,
boolean breakWhile = false; dn5T7a~
9Uk9TG5
2U#OBvNU
while(!bStop) @c.QrKSaD
{ Xv'64Nc!;
write_nPos(); tc# rL
Utility.sleep(500); guf+AVPno
breakWhile = true; ~%GUc ~
5a_K|(~3I
_39b8s{
for(int i=0;i<nStartPos.length;i++) A}oR,$D-
{ cvc.-7IO
if(!fileSplitterFetch.bDownOver) 'MC)%N,
{ 47t^{WrT
breakWhile = false; 9N-mIGJ
break; LWIU7dw
} jPbL3"0A&
} eQYW>z'%,
if(breakWhile) a:P% r
break; C0kwI*)
cIq3En
p%,JWZ[
//count++; x#pTB.
//if(count>4) m4kmJaM
// siteStop(); _u.l|yR
} cL`l1:j\}
..n-&(c32
N-vr_4{g
System.err.println("文件下载结束！"); #>!!#e!*
} EV~_-YC
catch(Exception e){e.printStackTrace ();} WlG/7$
} Zb}=?fcL;@
n1!u aUC
Yz{UP)TC
//获得文件长度 R=PjLH&)
public long getFileSize() i%-c/ lop
{ Q@l3XNH|c
int nFileLength = -1; ^>]p4Q3 6
try{ bD49$N?>
URL url = new URL(siteInfoBean.getSSiteURL()); u6|7P<HUfb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "esV#%:#J
httpConnection.setRequestProperty("User-Agent","NetFox"); iUSs)[]H>
*UEo&B2+
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int responseCode=httpConnection.getResponseCode(); ]l&_Pv!!
if(responseCode>=400) YMm Fpy
{ =FdS'<GM
processErrorCode(responseCode); S* <:He&1
return -2; //-2 represent access is error oBIKtS*L
} ~9x$tb x-
6h;$^3x$
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String sHeader; IWKQU/l!
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6B|IbQ^
for(int i=1;;i++) 9g "?`_
{ _.\p^ HM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); NlWIb2,
//Utility.log(in.readLine()); \}G/F!
sHeader=httpConnection.getHeaderFieldKey(i); D(L%fK`+
if(sHeader!=null) %hOe `2#$
{ &{l?j>|TM
if(sHeader.equals("Content-Length")) Vx?a&{3]-
{ .!=2#<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wVw3YIN#
break; _`ot||J
} ?l bK;Kv
} r=s2wjk
else |8V+(Vzl
break; \W#M]Q
} MheP@ [w|@
} 8]+hfB/
catch(IOException e){e.printStackTrace ();} 8+ Hho@=
catch(Exception e){e.printStackTrace ();} U%U%a,rA5s
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Utility.log(nFileLength); +=;F vb
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|<9R%
return nFileLength; \>M3E
} -pyTzC$HO
8"RX~Igf
APy&~`
//保存下载信息（文件指针位置） h<.&,6R
private void write_nPos() M%yT?R+
{ E}4R[6YD
try{ E+F!u5u
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1^Ci$ra
output.writeInt(nStartPos.length); 6|["!AUI
for(int i=0;i<nStartPos.length;i++) Z*x Q"+\
{ i>>_S&!9p
// output.writeLong(nPos); p\F*Y,4
output.writeLong(fileSplitterFetch.nStartPos); :/d#U:I
output.writeLong(fileSplitterFetch.nEndPos); #L[Atx
} l.Qj?G
output.close(); yv]/A<gP+
} @ L?7`VoE
catch(IOException e){e.printStackTrace ();} 7$}lkL
catch(Exception e){e.printStackTrace ();} EXoT$Wt{$
} 53@*GXzE
q9F(8-J
3S +.]v>
//读取保存的下载信息（文件指针位置） +-K-CXt
private void read_nPos() YG!~v~sV
{ oTT/;~I
try{ S'vrO}yU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )0~zL} )?
int nCount = input.readInt(); gz Qc
nStartPos = new long[nCount]; 7s1FJm=Y/
nEndPos = new long[nCount]; @My-O@C>
for(int i=0;i<nStartPos.length;i++) op/|&H'
{ -h8A<
nStartPos = input.readLong(); @6(4}&sEdm
nEndPos = input.readLong(); >o%.`)Ar
} *8t_$<'dQ
input.close(); S0,p:Wey
} b&s"x? 7
catch(IOException e){e.printStackTrace ();} Wyw/imr
catch(Exception e){e.printStackTrace ();} ~Wf&$p<|
} VuPa'2
34&n{ xv
GUJx?V/[
private void processErrorCode(int nErrorCode) MG<F.u
{ /87?U; |V
System.err.println("Error Code : " + nErrorCode); 7[.aAGTZ;
} }&bO;o&>
Y Dq5%N`
I?EtU/AD
//停止文件下载 Pur~Rz\\
public void siteStop() OZB(4{vnyC
{ )zf&`T
bStop = true; h/mmV:v
for(int i=0;i<nStartPos.length;i++) pa`"f&JO
fileSplitterFetch.splitterStop(); _.KKh62CN
Uf1i"VY
iQ~;to;Y
} D/5 ah_;
} .|G([O^H
//负责部分文件的抓取 vB hpD
**FileSplitterFetch.java ~$Xz~#~
*/ XcAx@CY9c
package NetFox; XFUlV;ek
T/X[q7O~~4
T;-&3
import java.io.*; eR$qw#%c*
import java.net.*; 2I3MV:5
]O,;t>
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public class FileSplitterFetch extends Thread { EuOrwmdj
xRuAt/aC
DZ<q)EpC
String sURL; //File URL & w&JE]$ 5
long nStartPos; //File Snippet Start Position o $7:*jU
long nEndPos; //File Snippet End Position ifHQ2Ug9
int nThreadID; //Thread's ID #/=s74.b
boolean bDownOver = false; //Downing is over q@1b{q#C5
boolean bStop = false; //Stop identical rF'_YYpr>
FileAccessI fileAccessI = null; //File Access interface AvfSR p
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,9SBGxK5`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |:7O
{ :70[zo7n'
this.sURL = sURL; nYhI0q
this.nStartPos = nStart; W|XW2`3p
this.nEndPos = nEnd; 7O',X Y
nThreadID = id; 8eCC =Az:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JPJ&k(P
} 0<d9al|J
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yr8 b?m.x
public void run() ]q~_
{ G6]W'Kk
while(nStartPos < nEndPos && !bStop) !VBl/ aU@
{ X,DG2HT
b*i_'k}*<g
f*)8bZDD
try{ >rJ9^rS
URL url = new URL(sURL); mwU|Hh)N]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !6{; z/Hy
httpConnection.setRequestProperty("User-Agent","NetFox"); 5 YjqN
String sProperty = "bytes="+nStartPos+"-"; %#kml{I
httpConnection.setRequestProperty("RANGE",sProperty); *DfwTbg|
Utility.log(sProperty); (1Q G]1q
=BW;n]ls
YflM*F`
InputStream input = httpConnection.getInputStream(); 6b`3AAGU"
//logResponseHead(httpConnection); eb&#sZ
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$2I^ ;5r[
byte[] b = new byte[1024]; 4BF \-lq~
int nRead; L+VqTt
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )nE=H,U?y
{ \JjZ _R
nStartPos += fileAccessI.write(b,0,nRead); G(joamfM
//if(nThreadID == 1) i286 J.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hq+j8w}<-
} }h{8i_R
{HoeK>rd
b`:n i
Utility.log("Thread " + nThreadID + " is over!"); 4k%y*L
bDownOver = true; jMFLd
//nPos = fileAccessI.write (b,0,nRead); G)5R iRcs
} sKDsps^$
catch(Exception e){e.printStackTrace ();} d7(g=JK<
} uknX py))
} &gGh%:`B
0G?*i_u\
3'3E:}o|
//打印回应的头信息 55LW[Pc
public void logResponseHead(HttpURLConnection con) @s7ZfV??
{ rx[l7F q
for(int i=1;;i++) [9N>*dKB
{ !C]2:+z-MF
String header=con.getHeaderFieldKey(i); lJlyfN
if(header!=null) H 5\k`7R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5 1&||.
Utility.log(header+" : "+con.getHeaderField(header)); olLVT<
else q%&JAX=
break; X"hdCY%
} pb8sx1.j;
} 9feVy\u
QT`|"RI%
~|CWy
public void splitterStop() LeP;HP|
{ *m$lAWB5D
bStop = true; nLvF^%P8
} 9pF@#A9p
OQ*BPmS-
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} ECW=865jL
WZh%iuI{C
D_s0)|j$cy
/* L[s7q0 F`l
**FileAccess.java z:gp\
*//文件访问(定位，写) "2m (*+
package NetFox; 'aV/\a:*
import java.io.*; NQ&\t[R[
r.z=
ZsnFuk#W
public class FileAccessI implements Serializable{ U=ek_FO
z.vERP56
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Qvc$D{z
RandomAccessFile oSavedFile; 3fBV SFVS
long nPos; *Rx&#9
qz_'v{uAj
_dQg5CmlG
public FileAccessI() throws IOException !vfbgK
{ <y`MUpf]
this("",0); ,;D$d#\"
} ?:woUTyCv
84U?\f@u
Py72:;wn
public FileAccessI(String sName,long nPos) throws IOException -|.Izgc
{ n5qg6(Tl]
oSavedFile = new RandomAccessFile(sName,"rw"); XK+" x!
this.nPos = nPos; Vd&&GI(:?^
oSavedFile.seek(nPos); gc6Zy|^V4`
} WPu-P
yw@kh^L
Q# Yba
public synchronized int write(byte[] b,int nStart,int nLen) aTWCX${~b
{ w!kWG,{C
int n = -1; x9!3i{_
try{ {r>iUgg
oSavedFile.write(b,nStart,nLen); j0wpaIp
n = nLen; |d)*,O4s
} :HiAjaA1pg
catch(IOException e) 9\ulS2d
{ d!P3<:+R[
e.printStackTrace (); m8ApiGG
} 1fOH$33
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7B@1[
return n; ;udV"7C
} ~[@gu,Wb
w\}@+w3b~
!'qY
} %iq8dAW%
\#(tI3
&02I-lD4+
/* G^%FP!'D?
**SiteInfoBean.java 0d|DIT#>?
*/ =F<bAZ
package NetFox; 7TU(~]Z
S*3*Q l*
YQ-!>3/)-
public class SiteInfoBean { )W,.xP
[:BD9V
\8<ZPqt9
private String sSiteURL; //Site's URL H_nIlku
private String sFilePath; //Saved File's Path CK=TD`$w
private String sFileName; //Saved File's Name UKpc3Jo:~
private int nSplitter; //Count of Splited Downloading File .+d.~jHX
E#zLm
k}&7!G@T
public SiteInfoBean() 4 \Ig<C9
{//nSplitter的缺省值为5 q]2t3aY%
//default value of nSplitter is 5 S HxD(6
this("","","",5); X/BcS[a
} wrhGZ=k{
^B?brH}
n@te.,?A"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mMOjV_
{ DJJd_
sSiteURL= sURL; MXa(Oi2Gg
sFilePath = sPath; j;yKL-ycB
sFileName = sName; p>=i'~lQ6
this.nSplitter = nSpiltter; v$)ZoM6E
:B7dxE9[r
L/c`t7
} +l27y0>t
vq` M]1]FO
+(U;+6 b
public String getSSiteURL() csjCXT=Ve
{ ,CxIA^
return sSiteURL; 90Bn}@t=Q
} *8Kx y@
vdaG?+_o
s9rKXY',:l
public void setSSiteURL(String value) M.oH,Kd6
{ up!54}qy
sSiteURL = value; 8G )O,F7z
} Ud& '*,
*!r"+?0gN
KXf(v4
public String getSFilePath() N8KH.P+
{ j"r7M|Z+V
return sFilePath; !nDiAjj
} q|ZzGEj:OV
V\nj7Gr:sF
)}$]~ f4R
public void setSFilePath(String value) 7h#*djef
{ gp<XTLJ@>
sFilePath = value; x8!uI)#tS
} {\vcwMUzZ
lx{ ' bzv
gvFs$X*^:
public String getSFileName() hw({>cH\
{ uk9!rE"
return sFileName; 7 -S?U~s
} +z|@K=d#|
e'A1%g)
#h}a
public void setSFileName(String value) ;_S DW
{ yu}yON
sFileName = value; hem>@Bp'V
} n{I1ZlEeh
,L=lg,lH^
Yb\d(k$h
public int getNSplitter() :/R>0n,
{ t{-*@8Ke
return nSplitter; ]@!3os,CNF
} l:+$Ks
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k&9[}a*
public void setNSplitter(int nCount) 0at['zw
{ wx8Qz,Z
nSplitter = nCount; }R!t/8K
} Ou`;HN;[
} \0n<6^y
&Jd_@F#J
dUL*~%2I
/* BA8g[TA7K
**Utility.java 3b?8<*
*/ ye-[l7
package NetFox; `ES+$O>
M#k$[w}=
xW|8-q
public class Utility { dpvEY(Ds
}g& KT!r
`=lo.c
public Utility() BtrMv6
{ @E4ya$A)F
Q`!^EyRA:^
~t1?oJ
} ~ycWcZi>
2f6BZ8H+Z
//线程睡眠 BvS!P8
public static void sleep(int nSecond) NJCSo(O
{ &2nICAN[
try{ L[^.pO
Thread.sleep(nSecond); sI6I5
} 7+;.Q
catch(Exception e) M8R/a[ -A
{ "R\D:Olb#
e.printStackTrace (); ,3 [FD9
} t?H sfN
} D?FmlDTr[
pVM1%n:#
//日志 *v$j n
public static void log(String sMsg) _*cKu>,O
{ [A'e7Do%'
System.err.println(sMsg); j\HZ5
} #^tnRfS"
%]1te*_
t&i4kS^y
public static void log(int sMsg) |\xTcS|d
{ Aho-\9/x%
System.err.println(sMsg); mV0u:ws
} A;k#8&;
} r4ljA@L
u2OrH3E4E3
26p_fKY
/* ?Y 5Vje[^
**TestMethod.java ehLn+tg
*/ < lUpvr
package NetFox; b2H-D!YO^
X]D:vuB
a'g&1N0Rc
public class TestMethod { 'w=aLu5dY
>2v<;.
X|yVRQ?F`
public TestMethod() 6n|][! f
{ ///xx/weblogic60b2_win.exe 4+89 M
try{ [_`@V4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k;K-6<^h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8|nc($}~
SiteFileFetch fileFetch = new SiteFileFetch(bean); x`Wb9[u8
fileFetch.start(); &Ez+4.srkh
} Fkg%_v$
catch(Exception e){e.printStackTrace ();} ^Rtxef
IBUFXzl
h;@>E:4Tg
} @yj~5Gf(j
:2V|(:^'
1,7 }ah_
public static void main(String[] args) <rvM)EJv|
{ hkRqtpYK
new TestMethod(); OdOn wY
} /([a%,DI
} 2PSkLS&IM
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