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)); r=vY-p
} >wt.)c?5
for(int i=0;i<nEndPos.length-1;i++) kD%MFT4
{ y%61xA`#
nEndPos = nStartPos[i+1]; xU0iz{9
} ^"54Q^SH
nEndPos[nEndPos.length-1] = nFileLength; h$6'9rL&i
} r^<,f[yH
} dh [kx
l5&5VC)
fR'!p: ~
//启动子线程 >3KlI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fHEIys,{
for(int i=0;i<nStartPos.length;i++) lX"m|W
{ 2y!aXk\#C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^v cnDi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0a8\{(w
nStartPos,nEndPos,i); h-;> v.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <jF&+[*iT
fileSplitterFetch.start(); S Z/yijf
} izaqEz
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3HYdb|y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A%F8w'8(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,IqE<i!U
nEndPos = " + nFileLength); !&g_hmnIF
// fileSplitterFetch[nPos.length-1].start(); 3Wbd=^hRvq
&y=OZ !M
3%1wQXr0
//等待子线程结束 A46q`l9B
//int count = 0; hZL!%sL7
//是否结束while循环 vo\'ycPv
boolean breakWhile = false; :.]EM*p?GV
b+J|yM<`
z _\L@b
while(!bStop) (@xC-*
{ ?hc=w2Ci
write_nPos(); %N~c9B
Utility.sleep(500); RMT9tXe*5
breakWhile = true; hp(MKfhH
/}>8|#U3y
wzd(=*N
for(int i=0;i<nStartPos.length;i++) D})/2O p
{ #-G@p
if(!fileSplitterFetch.bDownOver) jLI1Ed
{ y] D\i5Xv
breakWhile = false; &&P9T/Zks
break; zNrn|(Y%Y
} Q5Nbu90
} 3!gz^[!?EN
if(breakWhile) (:`4*xK
break; JU^Y27
nA(" cD[,
qp6'n&^&
//count++; H%U
//if(count>4) U2<q dknB
// siteStop(); H+Bon=$cE!
} =5B5
#TR!x,Hc
*K$a;2WjzG
System.err.println("文件下载结束！"); hp2E! Cma
} bF_0',W
catch(Exception e){e.printStackTrace ();} $poIWJMc
} *qSvSY*
zx=eqN@!@
F)Q[ cai
//获得文件长度 [|eIax xR,
public long getFileSize() XdV>6<gf{
{ !wpK +.D
int nFileLength = -1; mkyYs[
try{ lV^:2I/
URL url = new URL(siteInfoBean.getSSiteURL()); ejkUNCKQt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h;+O96V4.
httpConnection.setRequestProperty("User-Agent","NetFox"); >TCit1yD
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PDA9.b<q0
int responseCode=httpConnection.getResponseCode(); RS}_cm0
if(responseCode>=400) l{C]0^6>i
{ ]oSx]R>{f
processErrorCode(responseCode); YQd($
return -2; //-2 represent access is error fcF|m5
} NJr)f
S>(xx"Ia
H.{Fw j4
String sHeader; Ayqs~&{
4C_1wk('
5!Y\STn
for(int i=1;;i++) Wc+(xk
{ ,~Xe#eM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |&WYu,QQ4
//Utility.log(in.readLine()); h'h8Mm
sHeader=httpConnection.getHeaderFieldKey(i); H#hpaP;
if(sHeader!=null) Hkia&nz'3
{ 86-Rm
if(sHeader.equals("Content-Length")) ?r&~(<^z
{ AU`z.Isf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E8sM`2z5
break; I F!xZ6X8
} L,#YP#O,j
} rqN+0CT
else c)^A|{,G
break; AhOBbss]q
} RPeH[M^
} v*GS>S
catch(IOException e){e.printStackTrace ();} dZ(Z]`L,B
catch(Exception e){e.printStackTrace ();} t6KKfb
> _sSni
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Utility.log(nFileLength); i{$P.i/&
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8i73iTg(
return nFileLength; Z9 ws{8@_
} CUpRtE8@[_
YiuV\al
&XCd2
//保存下载信息（文件指针位置） Jf7H;ZM<
private void write_nPos() iN'T^+um=
{ NkBvN\CQ
try{ Hn)? xw]x
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^J7q,tvbJ
output.writeInt(nStartPos.length); ['\R4H!x
for(int i=0;i<nStartPos.length;i++) <BBzv-?D
{ +0ukLc@
// output.writeLong(nPos); &glh >9:G
output.writeLong(fileSplitterFetch.nStartPos); Pz2Q]}(w
output.writeLong(fileSplitterFetch.nEndPos); ~gZ1*8s`
} [olSgq!3
output.close(); jsgDJ}
} R#~l[S8u^
catch(IOException e){e.printStackTrace ();} dPpQCxf
catch(Exception e){e.printStackTrace ();} GR*sk#{
} Z*q&^/N
<`vXyPA6
RY)x"\D
//读取保存的下载信息（文件指针位置） ,|\\C6s
private void read_nPos() `g1?Q4h
{ yc7b%T*Y
try{ BWYv.&=(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m2(}$z3e
int nCount = input.readInt(); Ucy=I$"
nStartPos = new long[nCount]; dI7rx+L
nEndPos = new long[nCount]; lbovwj
for(int i=0;i<nStartPos.length;i++) r>bgCQ#-n
{ O!dS;p-F
nStartPos = input.readLong(); _8 K|2$X
nEndPos = input.readLong(); }eZ\~2
} ol_\ "
input.close(); !WlL RkwO
} 8lqmd1v
catch(IOException e){e.printStackTrace ();} 6 A]a@,PC
catch(Exception e){e.printStackTrace ();} 3*%+NQIj
} RfvvX$
5X];?(VTsb
Px?"5g#+
private void processErrorCode(int nErrorCode) u|$HA>F[
{ A~E S{Zkh
System.err.println("Error Code : " + nErrorCode); 8irTGA
} f&5S`}C
I'{Ctc
*< fJgc"3
//停止文件下载 p(GI02|n
public void siteStop() CL5^>.}
{ "-Nyf
bStop = true; p</t##]3ks
for(int i=0;i<nStartPos.length;i++) 8kU(>' ^_:
fileSplitterFetch.splitterStop(); l> H'PP~
'Tqusr>lPY
n9&fH
} `]GL3cIh:
} ti1R6oSn
//负责部分文件的抓取 V:5aq.o!
**FileSplitterFetch.java };9/J3]m
*/ *tpS6{4=#7
package NetFox; A9ld9R
4<1V
1l^[%0
import java.io.*; >{Mv+
import java.net.*; xgNV0;g,
#H Jlm1d
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public class FileSplitterFetch extends Thread { 0;`FS/[(f
%UooZO
h'G
String sURL; //File URL wt@TR~a
long nStartPos; //File Snippet Start Position [N[4\W!!
long nEndPos; //File Snippet End Position 0lq?l:/
int nThreadID; //Thread's ID Bo ywgL|
boolean bDownOver = false; //Downing is over ;QG8@ms|
boolean bStop = false; //Stop identical 6_yatq5c
FileAccessI fileAccessI = null; //File Access interface ~n0Exw(
C{l-l`:
Kt]vTn7!9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z{#3-O<a+n
{ `]19}GK~xo
this.sURL = sURL; M!gu`@@}F
this.nStartPos = nStart; 438r]f?0|{
this.nEndPos = nEnd; DrBkR`a?
nThreadID = id; jc>B^mqx
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9$[MM*r
} xo ^|d3
{s6#h#U
}NV<k
public void run() zU0JwZi
{ 86qQ"=v
while(nStartPos < nEndPos && !bStop) Um`KmM3
{ Ik5-ooZ&{
n2c(x\DA&
Ha ZV7
try{ v=dN$B5y3
URL url = new URL(sURL); q:jv9eL.O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lQ[JA[
httpConnection.setRequestProperty("User-Agent","NetFox"); K'"s9b8
String sProperty = "bytes="+nStartPos+"-"; =:R${F
httpConnection.setRequestProperty("RANGE",sProperty); dYwEVu6q
Utility.log(sProperty); 6+s&%io4
$j(4FyH\
r}|)oG,=
InputStream input = httpConnection.getInputStream(); 'f %oL/,
//logResponseHead(httpConnection); 7uv"#mq
Pq-@waH3
p ~+sk1[.
byte[] b = new byte[1024]; l% %cU"
int nRead; Zcc7 7dRA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 67Tu8I/r
{ MScUrW!TA
nStartPos += fileAccessI.write(b,0,nRead); qM^y@B2MO
//if(nThreadID == 1) Fo ,8"m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _ qQ
} NFur+zwv
Vj)"?|V
\0qFOjVj
Utility.log("Thread " + nThreadID + " is over!"); & }"I!
bDownOver = true; Tn3C0
//nPos = fileAccessI.write (b,0,nRead); 3XbFg%8YG
} Fghan.F
catch(Exception e){e.printStackTrace ();} EjEXev<]
} RdpOj >fT
} |VM=:}s&
`q\v~FT
lY[1P|]
//打印回应的头信息 McdK!V
public void logResponseHead(HttpURLConnection con) NY[48H
{ F[v^43-^_
for(int i=1;;i++) r|3u]rt
{ VWCC(YRU|$
String header=con.getHeaderFieldKey(i); J04R,B
if(header!=null) \naG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6,R<8a;Wn
Utility.log(header+" : "+con.getHeaderField(header)); >Ij#+=
else l,b_' m@
break; t#]VR7]
} 8L@@UUjr
} [R~@#I P!
M&/e*Ta5
hNp.%XnnZ
public void splitterStop() IeIv k55
{ lrMkp@f.
bStop = true; d;r,?/C
} Z\)P|#L$
yW"}%) d
_B}QS"A
} 6H|T )
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PCKxo;bD
/* fjQIuM
**FileAccess.java % <%r
*//文件访问(定位，写) ,fm{ krE
package NetFox; TjctK [db@
import java.io.*; R*vfp?x
>4T7DMy
$T2zs$
public class FileAccessI implements Serializable{ MB.LHIo
MY&?*pV)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V5I xZn%
RandomAccessFile oSavedFile; iW?NxP
long nPos; JQ\o[t
2 t]=-@
@c,=c+-
public FileAccessI() throws IOException @oMl^UYM=
{ 5pE@Ww
this("",0); .Ag)/Xm(?
} Vf(n
@d[)i,d:G
XToYtdt2
public FileAccessI(String sName,long nPos) throws IOException <,nd]a
{ 7^h*rL9
oSavedFile = new RandomAccessFile(sName,"rw"); D4+OWbf6
this.nPos = nPos; [rhK2fr:i
oSavedFile.seek(nPos); vRO`hGH
} V4%7Xj
4-xg+*()
}GGH:v
public synchronized int write(byte[] b,int nStart,int nLen) r*ry8QA
{ OgyHX>}bH
int n = -1; D_I_=0qNd
try{ 8GT{vW9
oSavedFile.write(b,nStart,nLen); 7I6&*I
n = nLen; pkA(\0E8
} B|BJkY'
catch(IOException e) W4AFa>h
{ G9> 0w)r
e.printStackTrace (); DTx>^<Tk
} O@KAh5EB
A Rjox`
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return n; sVIw'W
} a^9}ceu?
&R}2/Mt
/vFdhh
} `ve5>aw0_Y
4*+)D8
eN I6V/\`
/* uacVF[9|W
**SiteInfoBean.java EF'U`\gX
*/ p\,PY
package NetFox; ]3yaIlpD1
>K;C?gHo
ljj}XJQ
public class SiteInfoBean { :U#4H;kk~j
pd}af iF
0GiL(e|
private String sSiteURL; //Site's URL +t;j5\HS
private String sFilePath; //Saved File's Path ?-PW$p
private String sFileName; //Saved File's Name E.rfS$<1
private int nSplitter; //Count of Splited Downloading File ob>2SU[Y
&1Idv}@!
>PiEu->P,
public SiteInfoBean() Tk0Senq,
{//nSplitter的缺省值为5 r}])V[V
//default value of nSplitter is 5 X9n},}bJ"
this("","","",5); cH\.-5NQ
} |=4imM7
`Jon^&^;|
2UjQ!g`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *.NVc
{ I)X33X,
sSiteURL= sURL; 1C\[n(9
sFilePath = sPath; <al/>7z' O
sFileName = sName; 9mH/xP:y
this.nSplitter = nSpiltter; \P0>TWE
#+Cu&l
,Tc598D
} dJd(m&.|N
Q68q76
!XS ;&s7[*
public String getSSiteURL() go$zi5{h#
{ SdBo sB3v>
return sSiteURL; AE 2>smp5@
} a-7T
JN-wToOF
IHtNaN )
public void setSSiteURL(String value) ( RCQbI
{ Qf}b3WEAI
sSiteURL = value; ^iaG>rvA
} qY$/i#
G4eY}3F7,4
$@cg+Xrg1
public String getSFilePath() rXlJW]i
{ BliL1"".
return sFilePath; ril4*$e7^\
} Y-Gqx
\sZ!F&a~
E)w^odwMU
public void setSFilePath(String value) H"A|Z6y$^
{ VdV18-ea
sFilePath = value; ZkZTCb`/l
} 48 `k"Uy
6{p]cr
c31k%/.
public String getSFileName() m#a0HH
{ }?jL;CCe
return sFileName; @NS=
} kG>d^K
^ LTKX`p
\-B8`ah
public void setSFileName(String value) Lx:O Dd
{ 4 u!)QG
sFileName = value; c~a:i=y67
} !yQ#E2/A
A\7qPfpG
MjW g
public int getNSplitter() 8QN#PaY
{ =)GhrWeVi4
return nSplitter; i?&g;_n^
} H#luG_)
+84JvOkWi
Hki
public void setNSplitter(int nCount) s<t*g]0`/
{ P=%'2BQ{{
nSplitter = nCount; b+.P4+
} tz&oe
} S0 AaJty
uIkB&
2}P?N
/* L`Lro:E?kL
**Utility.java OTNcNY
*/ 1\_S1ZS
package NetFox; 5P'<X p
;LM,<QJ
IOx9".
public class Utility { W9ZfD~(3-
CVp`G"W:
8MH ZWi
public Utility() K(+ ~#$|-~
{ kCO`JAH#
!vB8Pk"
n.{Ud\|
} mBC?Pg
SW ^F
//线程睡眠 G G]4g)O5
public static void sleep(int nSecond) k/&~8l.$
{ 0T{Z'3^=
try{ Vnu*+
Thread.sleep(nSecond); #3l&N4/
} j~d<n_
catch(Exception e) jU~ !*]
{ y3 vDKZ
e.printStackTrace (); +O 2H":$
} _<`j?$P
} t7"vAjZU
Uk=-A @q
//日志 f,'gQ5\ X3
public static void log(String sMsg) brk>oM;t
{ 1Z5:DE<
System.err.println(sMsg); 2nL[P#r
} FaOfe]F
|]tIE{d
FOAy'76p
public static void log(int sMsg) VfK8')IXk
{ DeTx7i0
System.err.println(sMsg); biy1!r
} $n30[P@p;
} 3_:J`xX(4
D\}A{I92F4
TmZ% ;TN
/* {_GhS%
**TestMethod.java UQmdm$.
*/ bT^6AtsJ
package NetFox; =.Tc l"O[
%jgB;Y
}0&@J'<
public class TestMethod { 5.KhI<[
umt*;U=
2WK]I1_
public TestMethod() i$GL]0
{ ///xx/weblogic60b2_win.exe 8ug\GlZc
try{ E>t5/^c)*w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HAof,* h$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \>b :
SiteFileFetch fileFetch = new SiteFileFetch(bean); _sEkKh8x
fileFetch.start(); >l & N
} JVPl\I
catch(Exception e){e.printStackTrace ();} u|v2J/_5Y
,i>{yrsOh
@+OX1-dd/w
} noali96J
B:-qUuS?R
#nTzn2
public static void main(String[] args) ;<j[0~qp:
{ ?Vy%<f$
new TestMethod(); lV4|(NQ9
} vkFq/+'U
} eI%{/>
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