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)); tp*AA@~
} $+[HJ{
for(int i=0;i<nEndPos.length-1;i++) )n|:9hc
{ HcQ{ok9u
nEndPos = nStartPos[i+1]; ~"}-cl,
} 8u;l<^<
nEndPos[nEndPos.length-1] = nFileLength; rmR7^Ycv/
} a50{gb#
} zc,fJM
R0\E?9P
U#,2et6
//启动子线程 ;U}lh~e11
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t]"3vE>
for(int i=0;i<nStartPos.length;i++) t91v%L
{ }QG6KJh_%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HHoh//(\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z:9"7^+
nStartPos,nEndPos,i); WRFzb0;01
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W/{HZ<:.
fileSplitterFetch.start(); +l&ZN\@0X
} WZ"x\K-;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r#3_F=xL5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m]Z& .,bA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LfrS:g
nEndPos = " + nFileLength); &HZ"<y{j
// fileSplitterFetch[nPos.length-1].start(); 7PP76$
i6(y Bn
+<AX 0(
//等待子线程结束 `;4zIBJ
//int count = 0; jcOxtDTSW
//是否结束while循环 .#J'+LxFr
boolean breakWhile = false; ;9 XM s)
i~.L{K
/[t]m,p$yq
while(!bStop) =QOtag1;
{ `2d,=.X
write_nPos(); PS!f&IY}[.
Utility.sleep(500); ShHm7+fV
breakWhile = true; cq %=DZ
eA#J7=eC
AVi w}Y J
for(int i=0;i<nStartPos.length;i++) q}tLOVu1
{ d5+ (@HSR
if(!fileSplitterFetch.bDownOver) SS@#$t:
{ #ra:^9;Es:
breakWhile = false; SgFyv<6>:
break; Y-@K@Zu]?
} p?=rQte([
} +!dIEt).U
if(breakWhile) (PE"_80Z
break; pvP|.sw5G
ezCsbV;. [
!2tZ@ p|
//count++; x>;!`}x
//if(count>4) )1Os+0az
// siteStop(); zpiqJEf|'"
} &T}~h^/t
4vW:xK
!YsLx[+
System.err.println("文件下载结束！"); O,]t.1V
} \qi=Us|=
catch(Exception e){e.printStackTrace ();} xv9SQ,n<
} XNf%vC>
k P>G4$e_v
6}n>Nb;L"
//获得文件长度 Qp!r_a&
public long getFileSize() a@lvn/b2
{ tlQ3BKp
int nFileLength = -1; kdITh9nx<r
try{ S;MS,R
URL url = new URL(siteInfoBean.getSSiteURL()); d9sl(;r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iAbtv^fn
httpConnection.setRequestProperty("User-Agent","NetFox"); mz3!HksZ"
6#K1LY5}
X'IW&^kI
int responseCode=httpConnection.getResponseCode(); 'kL>F&|
if(responseCode>=400) {Z3B#,V(g
{ (p-a;.Twj
processErrorCode(responseCode); N3TkRJZ
return -2; //-2 represent access is error $F`jM/B6
} =sPY+~<o
3 =KfNz_
q[] "`?
String sHeader; pZuYmMP
Txj%o5G
a7)q^;:O
for(int i=1;;i++) kNMhMEez
{ Se%FqI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j^"Z^TEBT
//Utility.log(in.readLine()); mBhG"0:
sHeader=httpConnection.getHeaderFieldKey(i); qi.|oL9p
if(sHeader!=null) ;mu9;ixZ
{ cx&jnF#$
if(sHeader.equals("Content-Length")) Gyw@+(l
{ `QC{}Oo^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n1a;vE{!
break; \vs,$h
} L8Z[Ly+_
} 8tK8|t5+
else L/1?PM
break; 89Svx5S
} k 9R_27F
} l&dHH_m3
catch(IOException e){e.printStackTrace ();} E#URTt:&>
catch(Exception e){e.printStackTrace ();} #'mb9GWD3
KxqT5`P&
M6jP>fbV*
Utility.log(nFileLength); 2(YZTaY
<bDjAVq
:G?"BL5vP
return nFileLength; $Ud-aRlD
} @ZK#Y){
$M@SZknm
p)(mF"\8=
//保存下载信息（文件指针位置） .[? E1we
private void write_nPos() FZ6.<wN
{ :=UiEDN@
try{ Psp3~Kg
output = new DataOutputStream(new FileOutputStream(tmpFile)); )**k3u t4
output.writeInt(nStartPos.length); !Ui3}
for(int i=0;i<nStartPos.length;i++) _Z~wpO}/
{ ;<1O86!
// output.writeLong(nPos); \O/EY&
output.writeLong(fileSplitterFetch.nStartPos); E<1^i;F
output.writeLong(fileSplitterFetch.nEndPos); !:,d^L!bh
} kZs
output.close(); ?>N82#9Q
} ?"$W=*P\o
catch(IOException e){e.printStackTrace ();} 4d)w2t?H%
catch(Exception e){e.printStackTrace ();} ;``*]tY$
} 3Wrl_V
Ka1 F7b
HU-4k/I~
//读取保存的下载信息（文件指针位置） Hv>A$x$q
private void read_nPos() iOm~
{ L}ud+Wfox
try{ p#HPWW"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); c=<d99Cu!
int nCount = input.readInt(); C"PN3>x}j
nStartPos = new long[nCount]; hun LV8z
nEndPos = new long[nCount]; a5{CkM&,(
for(int i=0;i<nStartPos.length;i++) #m1e_[
{ UB@>i3
nStartPos = input.readLong(); 6|r` k75.
nEndPos = input.readLong(); : FF:{&d
} Z'6 o$Xv
input.close(); >|KfO>
} JAj<*TB.%
catch(IOException e){e.printStackTrace ();} aSi:(w
catch(Exception e){e.printStackTrace ();} L`cc2.F
} 7=N=J<]pl
^QTl(L
ICo_O] Ke
private void processErrorCode(int nErrorCode) yHLclv
{ >P/kb fPA
System.err.println("Error Code : " + nErrorCode); A0# K@
} eC%.xu^
Zk$AAjC&
`W e M
//停止文件下载 1wmS?
public void siteStop() j9XY%4.
{ =<s+cM
bStop = true; ,miU'<8tQ|
for(int i=0;i<nStartPos.length;i++) Ne,7[k
fileSplitterFetch.splitterStop(); _j-k*:
)fP,F(
8X][TJG$
} V=Iau_
} B9KY$^J
//负责部分文件的抓取 |jJC~/WR
**FileSplitterFetch.java )I9AF,K
*/ Y=sRVypJ
package NetFox; Mii-Q`.:
Na=9ju
I! {AWfp0
import java.io.*; Wxkk^J9F3
import java.net.*; Qf0$Z.-
Gy.<gyK9
17tph;
public class FileSplitterFetch extends Thread { .qi$X!0
aCcBmc
S&}7jRH1
String sURL; //File URL EShc1KPqc
long nStartPos; //File Snippet Start Position 1el?f>
long nEndPos; //File Snippet End Position Q4{%)}2$
int nThreadID; //Thread's ID daE/v.a4|
boolean bDownOver = false; //Downing is over @4^5C-
boolean bStop = false; //Stop identical L^yQb4$&M
FileAccessI fileAccessI = null; //File Access interface E D*=8s2
h']RP
YN_#x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RQWVjF#
{ t }7hD
this.sURL = sURL; "B*a| 'n!
this.nStartPos = nStart; ,w,>pO'[
this.nEndPos = nEnd; #R4Mv(BG
nThreadID = id; s+(%N8B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7f8%WD)
} H[@uE*W
TyD*m$`y
8jd<|nYnfc
public void run() ~0w7E0DE[
{ J5)e 7
while(nStartPos < nEndPos && !bStop) 91r9RG>
{ &eQzfx=|km
C6,GgDH`
p18-yt; 1
try{ D-9zg\\'`
URL url = new URL(sURL); ?aEBS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'Y(#Yxc
httpConnection.setRequestProperty("User-Agent","NetFox"); gP/[=:
String sProperty = "bytes="+nStartPos+"-"; DQP#h5O
httpConnection.setRequestProperty("RANGE",sProperty); 2!\y0*}K
Utility.log(sProperty); >&TSz5Q
wXPNfV<(2
FXV=D_G}
InputStream input = httpConnection.getInputStream(); #x1AZwC
//logResponseHead(httpConnection); @k<RX'~q
qF`;xa%,}
~"\sL;B
byte[] b = new byte[1024]; o+;=C@,'
int nRead; \=Af AO@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zT#36+_?
{ '!Ps4ZTn_
nStartPos += fileAccessI.write(b,0,nRead); T~cq=i|O
//if(nThreadID == 1) $^ (q0zR~l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Iwi>yx8
} <*0MD6$5
gGw6c" FRQ
N#@xo)-H
Utility.log("Thread " + nThreadID + " is over!"); 8A"[n>931
bDownOver = true; DBAJkBs
//nPos = fileAccessI.write (b,0,nRead); VH4P|w[YF
} %}%D8-d}G
catch(Exception e){e.printStackTrace ();} /O|!Sg{
} ehtiu!Vk
} (M4~N)7<P5
>C+0LF`U
3:<+9X
//打印回应的头信息 Ky|Hi3?
public void logResponseHead(HttpURLConnection con) Jme}{!3m
{ B/q/sC
for(int i=1;;i++) kF3 EJ
{ c=I!?a"
String header=con.getHeaderFieldKey(i); cBmo#:>'
if(header!=null) 0!9vGs
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g-pDk*|I,Q
Utility.log(header+" : "+con.getHeaderField(header)); ,r{*o6
else 4U<'3~RN
break; <]/`#Xgh
} m}:";>?#
} 2n?\tOm(V
583ej2HPg
#jd?ocoY
public void splitterStop() ,a?)#X
{ _Jk-nZgn
bStop = true; SOb17:o3|
} $JqdI/s
~53E)ilB
CEc& G
} V:6#IL
-Hh$3Uv
UYW%%5p?
/* v!t*Ng
**FileAccess.java |o~FKy1'z\
*//文件访问(定位，写) Vyj>&"28
package NetFox; 1]A%lud4
import java.io.*; $Bz|[=
JnhHV(H
q\O'r[&V
public class FileAccessI implements Serializable{ E?y0UD[8J
-yg9ug
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _E)xR
RandomAccessFile oSavedFile; \9Itu(<f
long nPos; 9V?MJZ@aG
AS|gi!OVA
P0RMdf
public FileAccessI() throws IOException / Zz2=gDY
{ qzE/n
this("",0); QoDWR5*^D
} ^*A/92!yF
174H@
fB1JU1
public FileAccessI(String sName,long nPos) throws IOException miuJ!Kr'
{ ]j*o&6cQf
oSavedFile = new RandomAccessFile(sName,"rw"); Xu3^tH-b<
this.nPos = nPos; _M:)x0("
oSavedFile.seek(nPos); dLD"Cx
} a&#Z=WK4
1)#<nk)I
~IE:i-Kz
public synchronized int write(byte[] b,int nStart,int nLen) g]$>G0E`oD
{ 5Ag]1k{
int n = -1; $msT,$NJ
try{ da\K>An>
oSavedFile.write(b,nStart,nLen); s?~Abj_
n = nLen; dT/Cn v=
} uz>s2I}B
catch(IOException e) m{pL< g^M
{ (oq(-Wv
e.printStackTrace (); @WhcY*R2
} akm)X0!-}
xVfJ]Y
uAzVa!)
return n; "uGJ\
} J9/9k
s]L`&fY]O
'QeqWn
} '9auQ(2
rM[Ps=5
*Ei~2O}
/* |YZ`CN<
**SiteInfoBean.java QV{Nq=%]
*/ <FS/'[P
package NetFox; l:+tl/
. Nog.
4I:Jb;k>
public class SiteInfoBean { (`3Bi]7
@=Ly#HuUM
umrRlF4M;
private String sSiteURL; //Site's URL <6dD{{J]>p
private String sFilePath; //Saved File's Path 8Y5* 1E*
private String sFileName; //Saved File's Name rRT9)wDa
private int nSplitter; //Count of Splited Downloading File b\=0[kBQw
;a{ Dr
C9gF2ii|?
public SiteInfoBean() deHBY4@
{//nSplitter的缺省值为5 ywq{9)vq
//default value of nSplitter is 5 Esw&ScBOP
this("","","",5); jXZKR(L
} a2dF(H
.4_~ku
g'pE z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =C`v+NPM)|
{ rZJp>Q)s
sSiteURL= sURL; G9E?
sFilePath = sPath; g^B6NF
sFileName = sName; M/UJb1<
this.nSplitter = nSpiltter; LYWQqxB
iY;)R|6
ucoBeNsHx
} =b`>ggw#
Oo7n_h1
G92=b*x/
public String getSSiteURL() N1LR _vS"
{ XHN?pVZ7
return sSiteURL; R#1m_6I
} Hd;>k$B
? ~_%I
Lb2Bu>
public void setSSiteURL(String value) NNe'5q9
{ z W+wtYV4
sSiteURL = value; ,0-
} 4RTEXoXs
YnJ=&21
?_HTOOa
public String getSFilePath() !o*oT}6n
{ j:<E=[Kl
return sFilePath; i]Kq
} [W^6=7EO
O~qB
?:U6MjlQ"{
public void setSFilePath(String value) x!I7vs~~zW
{ xg3G
sFilePath = value; 4jG@ #
} dr9I+c7u
nHZ 4):`
>St
public String getSFileName() c:=Z<0S;
{ I*ho@`U
return sFileName; vKaX,)P;?
} nH[@EL
r43dnwX
|nm,5gPNC
public void setSFileName(String value) Yq1 ~"he8
{ jRgv 8n
sFileName = value; Q|pz].0
} &=02.E@
[=V8
{`J7>K
public int getNSplitter() J3q}DDnEo
{ W:9L!+m^
return nSplitter; v[Ar{t&
} a2).Az
N18Zsdrp
&3u* zV$
public void setNSplitter(int nCount) Yt|{l
{ v{%2`_c
nSplitter = nCount; kP[ Y
} 4AP<mo
} :=~([oSNW"
r-'j#|^tz
R \`,Q'3
/* \UNw43EL
**Utility.java N:&^ql4
*/ H 5sj% v
package NetFox; [8)Zhw$
t3bN PK^
b,SY(Ce~g
public class Utility { )ZiJl5l@
%PkJ7-/b|^
Rjh/M`|
public Utility() t%8*$"~X
{ N'[^n,\(:
`D?vmSQ
(a)d7y.oo
} kyY tL_SD
;PLby]=O
//线程睡眠 -ud!j
public static void sleep(int nSecond) /B1NcRS
{ r--"JO%2
try{ \&W~nYXq"
Thread.sleep(nSecond); !FO||z(vb
} sq :ff
catch(Exception e) pLk?<y
{ t,=khZ
e.printStackTrace (); u1>|2D
} N$_Rzh"9rr
} @-u/('vpB
K3\U'bRO
//日志 L*L3;y|
public static void log(String sMsg) uFECfh
{ 6'*?zZrz
System.err.println(sMsg); k6*2= xK~
} Ng;E]2"
W%Ky#!\-
.;$/nz6vk
public static void log(int sMsg) j_ :4_zdBy
{ Iy`Zh@"~
System.err.println(sMsg); 3YRhqp"E
} gv<9XYByt
} 4}?Yp e-
A u(Ngq
!xa,[$w(^
/* <L5[#V_
**TestMethod.java %JiA,
*/ Vl'|l)b4W
package NetFox; BBy/bc!
8HTV"60hTs
oYqlN6n,=6
public class TestMethod { b]*9![_
<EpP;
(u$Q
public TestMethod() m2VF}% EIr
{ ///xx/weblogic60b2_win.exe ~":?})
try{ "-^TA_XfI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Af*^u|#
SiteFileFetch fileFetch = new SiteFileFetch(bean); u^V`Ucd"R
fileFetch.start(); vp-)$f&
} Pk*EnA)
catch(Exception e){e.printStackTrace ();} 5z#>>|1>#
-*tP_=-Dg
J^1w& 40
} 9Y*6AaKE6
pspV~9,
dr:)+R
public static void main(String[] args) V&NOp
{ ^$yr-p%-
new TestMethod(); [l'~>
} PsLuyGR.<
} =;c? 6{<1
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