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)); 1Wz5Iv#Ez
} 9KMtPBZ
for(int i=0;i<nEndPos.length-1;i++) goc"+K
{ NQ,2pM<*-
nEndPos = nStartPos[i+1]; cL:hjr"
} 3jw4#GW
nEndPos[nEndPos.length-1] = nFileLength; yi,Xs|%.
} xDIl
} L4{+@T1A[
1V;,ZGI*
]9~6lx3/
//启动子线程 ^2uT!<2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o.])5i_HV
for(int i=0;i<nStartPos.length;i++) 2Y%E.){
{ J pKCux
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3.@ir"vy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), j\2q2_f
nStartPos,nEndPos,i); 9Nu:{_YoP
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >RXDuCVi
fileSplitterFetch.start(); 'V}4_3#q
} 9tIE+RD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j_}f6d/h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,pa=OF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #A^(1
nEndPos = " + nFileLength); J;Eg"8x]
// fileSplitterFetch[nPos.length-1].start(); 1qhSN#s{_
q[%SF=~<k{
$i$Z+-W4'
//等待子线程结束 >0I\w$L
//int count = 0; :6W* ;<o
//是否结束while循环 xN44>3#
boolean breakWhile = false; zOMU&;.\
`,)%<}
M$2lK^2L
while(!bStop) EN)0b,ax
{ 2,G9~<t
write_nPos(); 'Jl73#3
Utility.sleep(500); =7-@&S=?s
breakWhile = true; d.p%jVO)"
E~1"Nh
K"VRHIhfg
for(int i=0;i<nStartPos.length;i++) |%fM*F^7/
{ 6='x}Qb\H
if(!fileSplitterFetch.bDownOver) =VF%Z[Gm
{ \(ju0qFqH
breakWhile = false; -qJO6OM
break; Il$Jj-)
} 8Oo16LPD
} nH|7XY9"
if(breakWhile) %Q|Hvjk=E
break; lM[FT=M
1^y^b{
)%~<EJ*&Z
//count++; myDcr|j-a
//if(count>4) 8J8@0
// siteStop(); ~P!%i9e_
} 8Xz \,}$O
(r"2XXR
r*t\F&D
System.err.println("文件下载结束！"); fk(h*L|sI
} YFs!,fw'
catch(Exception e){e.printStackTrace ();} w7yz4_:x^
} %#@5(_'
h3P^W(=&
$WG<
//获得文件长度 :PQvt/-'(D
public long getFileSize() U )J/so)
{ ^-26K|{3
int nFileLength = -1; /U@Y2$TOF
try{ @tPptB
URL url = new URL(siteInfoBean.getSSiteURL()); d8M8O3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]McDN[h:
httpConnection.setRequestProperty("User-Agent","NetFox"); g5~wdhpb
u51Lp
7/6%92T/B
int responseCode=httpConnection.getResponseCode(); \mDBOC0eK
if(responseCode>=400) BVv{:m{w
{ l&uBEYx
processErrorCode(responseCode); N_f>5uv
return -2; //-2 represent access is error >d$Sh`a6
} gtRs||
z#\YA]1
ZUaqv
String sHeader; |/O_AnGI
'Sjt*2blq
Y%@a~|
for(int i=1;;i++) ++Fk8R/$U[
{ 6}GcMhU<r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .X{U\{c|a
//Utility.log(in.readLine()); aui3Mq#f
sHeader=httpConnection.getHeaderFieldKey(i); Iz[wrtDI1
if(sHeader!=null) bSS=<G9
{ +X!QH/ 8
if(sHeader.equals("Content-Length")) _Wgpk0
{ Bngvm9k3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lIgAc!q(
break; eX <@qa4<
} lH%-#2]
} Rge\8H/z
else `6 ?.ihV
break; "i~~Q'=7
} )UAkg
} ZA'Qw2fF0
catch(IOException e){e.printStackTrace ();} ZMmf!cKY:'
catch(Exception e){e.printStackTrace ();} "E%3q3|"l
6G]hsgro
c^`(5}39v
Utility.log(nFileLength); Pze{5!
`E-cf7%
R6-Z]Hu
return nFileLength; FmC [u
} \Ea(f**2B
T/TMi&:?.
i[m-&
//保存下载信息（文件指针位置） }g_\?z3gt
private void write_nPos() 9hdz<eFL
{ |J^$3RX
try{ s!WI:E7
output = new DataOutputStream(new FileOutputStream(tmpFile)); |!"qz$8fB
output.writeInt(nStartPos.length); @]X5g8h
for(int i=0;i<nStartPos.length;i++) C,nU.0
{ H:.l:PJ
// output.writeLong(nPos); MNd[Xzm
output.writeLong(fileSplitterFetch.nStartPos); (5Sv$Xt
output.writeLong(fileSplitterFetch.nEndPos); w~}.c:B
} 6'qu[~}Q
output.close(); 'uU{.bq
} _e94
catch(IOException e){e.printStackTrace ();} `rZS\A
catch(Exception e){e.printStackTrace ();} 1$1P9x@H
} :V^|}C#
5nv1%48Ri
nbdjk1E`~
//读取保存的下载信息（文件指针位置） 6$LQO),,
private void read_nPos() ]c\d][R N
{ % n~ 'UA
try{ )@a_|q@V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x0$#8
int nCount = input.readInt(); (?lKedA>2
nStartPos = new long[nCount]; W^N|+$g>H
nEndPos = new long[nCount]; jxTYW)E
for(int i=0;i<nStartPos.length;i++) {q|Om?@
{ -9~WtTaV.H
nStartPos = input.readLong(); EN{o3@ O'
nEndPos = input.readLong(); lq}g*ih
} AQIBg9y7
input.close(); tLo_lLn*~%
} q-TDg0
catch(IOException e){e.printStackTrace ();} \cW9"e'
catch(Exception e){e.printStackTrace ();} )|j?aVqZ
} %3mh'Z -[f
iuS*Vw
)T!3du:M
private void processErrorCode(int nErrorCode) klSAY
{ SRek:S,
System.err.println("Error Code : " + nErrorCode); 10W6wIqK
} C7xmk;c w
OGAC[s~V
B8.uzX'p
//停止文件下载 6uKS!\EY|
public void siteStop() :C9vs
{ \TnRn(Kw
bStop = true; )k6kK}
for(int i=0;i<nStartPos.length;i++) 'O[0oi&
fileSplitterFetch.splitterStop(); h#(J6ht
m\e?'-(s
C5x*t Q|
} 7j8Ou3
} aYws{Vii
//负责部分文件的抓取 @t4OpU<'*b
**FileSplitterFetch.java sX,S]:X
*/ %2^wyVkq:
package NetFox; ?OF9{$m3?
vx}W.6C}
*5d6Q
import java.io.*; W?X3 :1c9:
import java.net.*; O8)N`#1>+
%hCd*[Z}j
8=,-r`oNy
public class FileSplitterFetch extends Thread { `PS>"-AY2
L=wpZ`@ y
'e:(61_
String sURL; //File URL ki'CW4x
long nStartPos; //File Snippet Start Position SkyX\&
long nEndPos; //File Snippet End Position zLybf:#
int nThreadID; //Thread's ID 'ZAl7k .
boolean bDownOver = false; //Downing is over Q?/qQ}nNw
boolean bStop = false; //Stop identical R(p3*t&n
FileAccessI fileAccessI = null; //File Access interface 6o<(,\ad[
uS7kkzt-x
Nx=rw h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6QAhVg: A
{ S pk8u4
this.sURL = sURL; ($'5xPb
this.nStartPos = nStart; ':!aFMj^
this.nEndPos = nEnd; JsHD3
nThreadID = id; C1o^$Q|j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Fx )BMP
} M.\V/OX
4/AE;yX
OxqkpK&
public void run() SVBo0wvz-
{ }56WAP}Z 4
while(nStartPos < nEndPos && !bStop) >)+N$EN
{ _BZ6Ws$C2
xQkvK=~$
|H.ARLS
try{ bXk(wXX
URL url = new URL(sURL); Dvm[W),(k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pD;fFLvN
httpConnection.setRequestProperty("User-Agent","NetFox"); :f~qt%%/
String sProperty = "bytes="+nStartPos+"-"; }/2M?W0
httpConnection.setRequestProperty("RANGE",sProperty); (9Q@I8}Iy
Utility.log(sProperty); *" +u^
ZQ{-6VCjl
{A'_5 X9
InputStream input = httpConnection.getInputStream(); Z}S7%m
//logResponseHead(httpConnection); H{hzw&dZ<P
YO9;NA{sH
S?#6{rx
byte[] b = new byte[1024]; v1z d[jqk
int nRead; %rJ'DPs
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LB`{35b-
{ oL@K{dk
nStartPos += fileAccessI.write(b,0,nRead); `T{'ufI4B
//if(nThreadID == 1) hlmeT9v{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @MO/LvD
} ><I{R|bC
lBGYZ--
)6(|A$~C+
Utility.log("Thread " + nThreadID + " is over!"); 3,-[lG@o
bDownOver = true; 5bBCI\&sam
//nPos = fileAccessI.write (b,0,nRead); yxAy1P;dX
} |Wr$5r
catch(Exception e){e.printStackTrace ();} )+|Y;zC9
} FG^lh
} sE&1ZJ]7
HI7w@V8Ed
Xyr'rm5+b
//打印回应的头信息 (AZAQ xt
public void logResponseHead(HttpURLConnection con) glLoYRTi
{ %77uc9}
for(int i=1;;i++) p>B-Ubu
{ <Xw\:5 F<7
String header=con.getHeaderFieldKey(i); QJ!2Vw4K
if(header!=null) yK-DzAv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); { &Vt]9
Utility.log(header+" : "+con.getHeaderField(header)); ~;#sj&~
else :IucH%6V
break; OY8P
} 3g3f87[
} W/g_XQ
M.+h3<%^
_s*p$/V\
public void splitterStop() -Nn<pq
{ t&Q(8Hz
bStop = true; No`*->R
} hZlHY9[t?
B<i(Y1n[
zK&1ti@wln
} ,3N>`]Km'
*2pf>UzL
4:-x!lt
/* uehu\umt=
**FileAccess.java )/)[}wN;j
*//文件访问(定位，写) x"!`JDsS
package NetFox; BoxtP<C"
import java.io.*; Jy\0y[f*
R9!U_RH
YxrMr9>l1
public class FileAccessI implements Serializable{ ` FOCX;
4XAs^>N+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "blq)qo)
RandomAccessFile oSavedFile; lV$CBS
long nPos; )K$YL='kX
;dPaWS1D
U!NuiKaQ26
public FileAccessI() throws IOException zXD/hM
{ h8X[*Wme
this("",0); lrj&60R`w
} bv VkN
b$yIM
&>]U c%JK
public FileAccessI(String sName,long nPos) throws IOException 6~Dyr82"B
{ *V7mM?
oSavedFile = new RandomAccessFile(sName,"rw"); Yxbg _RQm
this.nPos = nPos; T*%rhnTv0
oSavedFile.seek(nPos); O-[
} "{\xBX~oM
{Wi*B(
H6{Bx2J1*
public synchronized int write(byte[] b,int nStart,int nLen) '&e8;X
{ FvY=!U06
int n = -1; k1oJ<$Q
try{ DP0@x+`k
oSavedFile.write(b,nStart,nLen); _GFh+eS}
n = nLen; 1Iy1xiP
} mt$rjk=
catch(IOException e) '%wSs,HD
{ m#8(l{3|
e.printStackTrace (); %S%IW
} Hi$R"O (
@6|<c
(xHu@l!]
return n; i1XRBC9
} AO>b\,0Me
U[02$gd0l
TA0(U$ 4
} A]TEs)#*7)
V?1[R
Li]96+C$}
/* ('7$K
**SiteInfoBean.java df$.gP
*/ w%s];EE
package NetFox; :L@n(buRN
dW%t ph
r{^43g?
public class SiteInfoBean { CgmAxcK
D=mmBo
pZ}B/j
private String sSiteURL; //Site's URL n1{[CCee@
private String sFilePath; //Saved File's Path =Y81h-
private String sFileName; //Saved File's Name 4>i\r
private int nSplitter; //Count of Splited Downloading File =\|,hg)c
%~x?C4L8
=PciLh
public SiteInfoBean() C\;l)h_{
{//nSplitter的缺省值为5 "+T`{$Z=C
//default value of nSplitter is 5 '?| 1\j
this("","","",5); +Wg/O -
} Jw8?o/1D@
}x\#ul)
`-.2Z 0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pB\:.?.pd
{ DqT<bNR1*;
sSiteURL= sURL; Y(bB7tR
sFilePath = sPath; r'j88)^
sFileName = sName; ij;NM:|Sd
this.nSplitter = nSpiltter; \fUX_0k9,
Te L&6F$
in/~' u
} S'8+jY
cI'n[G
xi(1H1KN5B
public String getSSiteURL() 'fl< ac,.
{ 9D+k71"+
return sSiteURL; $] "M`h
} ?bVIH?
l[c '%M|N
0t%]z!
public void setSSiteURL(String value) e}1Q+h\
{ p|.5;)%|
sSiteURL = value; Jh0Grq
} " Q?~LB
wR@>U.XT@
YB7n}r23
public String getSFilePath() %L*EB;nK
{ ~Ym_ {
return sFilePath; Q;8z&4s@
} MGsQF#6]
Qgj# k
OU/}cu
public void setSFilePath(String value) Lm~<BBp.
{ ;7qIm83
sFilePath = value; 38p"lT
} H^*AaA9-
A6]X aF
M,_ $s,
public String getSFileName() G|KA!q
{ Z8ea)_{#
return sFileName; G|f9l?p
} cVW7I
BYXc 'K
Zh;wQCDj
public void setSFileName(String value) }W8A1-UF
{ B6 (\1
sFileName = value; 0>Snps3*Z
} .)b<cH~%
(cOe*>L;
|Q3d7y
public int getNSplitter() &L$9Ii
{ zp;!HP;/=
return nSplitter; 1*u]v{JJ(
} 7Dbm s(:(
]|tg`*l!>
Cjr]l!
public void setNSplitter(int nCount) RbTGAA
{ @@H_3!B%4v
nSplitter = nCount; B4RrUA32
} PM[_0b
} ?h&XIM(
5<dg@,\
MSQ^ovph
/* ]nUrE6
**Utility.java g~y0,0'j1\
*/ ~^' ,4<K-}
package NetFox; F]yB=
!92e$GJ} ;
6/S.sj~
public class Utility { oYkd%N9P
U_"!\lI_yg
Fn@`Bi?#q
public Utility() d j\Z}[
{ XYzaSp=bb
lf7bx}P*
F)hj\aHm k
} 9Vm1q!lE
][S q^5`
//线程睡眠 6XWNJb
public static void sleep(int nSecond) %m |I=P
{ ZX:rqc
try{ }4YzP 4
Thread.sleep(nSecond); HXa[0VOx
} .g*N+T6O
catch(Exception e) X>[i<ei
{ (0NffM1
e.printStackTrace (); mp8GHV
} 88osWo6rG
} 60!%^O =
_eiqs
//日志 i7.8H*z'
public static void log(String sMsg) tRdf:F\X
{ .U0Gm_c0
System.err.println(sMsg); Jr!BDg
} tdH[e0x B
gPKf8{#%e
r& a[?
public static void log(int sMsg) G(a5@9F
{ RhE~Rwbx
System.err.println(sMsg); [j0[c9.p[
} +=8wZ]
} |ky40[C
*,$5EN
cb9-~*1
/* 4]U=Y>\Sr
**TestMethod.java _cs(f<>oCO
*/ T o["o!(;z
package NetFox; }d?;kt
GJ*IH9YR
}i~k:kmV
public class TestMethod { 1<BKTMBq?{
Dds-;9
K'ZNIRr/C
public TestMethod() !vgY3S0?rq
{ ///xx/weblogic60b2_win.exe ;0 B1P|7zK
try{ _&/`-"3y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /^.S nqk
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8${n}}
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;-Yvi,sS+
fileFetch.start(); TWpw/osW
} = J;I5:J
catch(Exception e){e.printStackTrace ();} x 7by|G(
z{L'7
4{uQ}ea
} d%8n
d-~V.
srv4kodj
public static void main(String[] args) G JRl{Y
{ S1|u@d'
new TestMethod(); `yv?PlKL
} eyMn! a
} a*cWj}u
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