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)); FIS "Z(
} {rDq_^
for(int i=0;i<nEndPos.length-1;i++) JGis"e
{ pw\P<9e=
nEndPos = nStartPos[i+1]; oR#Ob#&
} >g]ON9CGH
nEndPos[nEndPos.length-1] = nFileLength; <UT>PCNG
} N'QqJe7Z
} JaI Kjn
!p',Za
7\X$7
//启动子线程 &?y7I Pp
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RkA8
for(int i=0;i<nStartPos.length;i++) +P)ys#=
{ {~'H
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &iBNO,v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CW p#^1F
nStartPos,nEndPos,i); 1'Rmg\(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Xh}&uZ`A
fileSplitterFetch.start(); FY4T(4#
} y^R4I_* z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <( EyXV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wt?o 7R2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D:9 2\l
nEndPos = " + nFileLength); bq NP#C
// fileSplitterFetch[nPos.length-1].start(); ,EI:gLH
YG`?o
kAo.C Nj7
//等待子线程结束 e)b%`ntF
//int count = 0; s$ z2 c
//是否结束while循环 {$33B'wk
boolean breakWhile = false; KmmQ,e%
2khh4?|\
e;h,V(
while(!bStop) 4-^[%&>}
{ 0[Eb .2I
write_nPos(); ykmv'a$-4
Utility.sleep(500); v@n_F
breakWhile = true; E oe}l
t,HFz6
! %Ny0JkO
for(int i=0;i<nStartPos.length;i++) ?aWx(dVQ
{ :o8MUXH$
if(!fileSplitterFetch.bDownOver) hqDqt"dKz
{ 9:8|)a(1
breakWhile = false; 8:dQ._#v
break; 5FOqv=6S
} -[heV|$;
} {v,)G)obWw
if(breakWhile) -c+]Wm"\
break; *yez:qnx
9]7u_
jatr/
//count++; 5k$vlC#[H
//if(count>4) HdNnUDb$B
// siteStop(); !0"nx{7.
} Zh'&-c_J
d1G8*YO@
/{*$JF
System.err.println("文件下载结束！"); Qihdn66
} :NE/Ddgc'
catch(Exception e){e.printStackTrace ();} f<=Fe:1.
} x?sI;kUw8
,H[SI0];
J=H)JH3
//获得文件长度 GLUUY0
public long getFileSize() k\aK?(.RC7
{ rLv;Y
int nFileLength = -1; `hUHel;6
try{ @D[`Oj)
URL url = new URL(siteInfoBean.getSSiteURL()); r\qz5G *6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /.Q4~Hw%}
httpConnection.setRequestProperty("User-Agent","NetFox"); |5MbAqjzC
`^6 ,kI-c
@dEiVF`4:
int responseCode=httpConnection.getResponseCode(); 75NRCXh.
if(responseCode>=400) OH'ea5xq
{ "rNL `P7
processErrorCode(responseCode); SSA W52xC
return -2; //-2 represent access is error C5X(U:
} |.U)ll(c
Adx`8}N8
$/Ov2z
String sHeader; L:R<e#kgS
\#Up|u:
]Kh2;>= Xj
for(int i=1;;i++) 8Vn4.R[vE
{ /,tAoa~FA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (S/F)?
//Utility.log(in.readLine()); 6v732;^
sHeader=httpConnection.getHeaderFieldKey(i); 46No%cSiG
if(sHeader!=null) A)NkT`<)
{ s V }+eU
if(sHeader.equals("Content-Length")) =RKSag&
{ bF-"tm
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VaLs`q&3>
break; }NCL>l;q
} /aqEJGG>
} +%0z`E\?M#
else `I;F$`\
break; K5 KyG
} \ |!\V
} E>uVofhml
catch(IOException e){e.printStackTrace ();} 'Jj=RAV`
catch(Exception e){e.printStackTrace ();} 57I}RMT"
8P: spD0
#&8rcu;/
Utility.log(nFileLength); [V}, tO|
iK;opA"
CIC[1,
return nFileLength; Lx[ ,Z,kD
} diT=x52
cgT
(<c7<_-H
//保存下载信息（文件指针位置） =|U@
private void write_nPos() WO*9+\[v
{ B80aw>M
try{ e%O0hE
output = new DataOutputStream(new FileOutputStream(tmpFile)); ftbpqp'
output.writeInt(nStartPos.length); 01@t~v3!Z
for(int i=0;i<nStartPos.length;i++) 7hw .B'7
{ 04@cLDX8uB
// output.writeLong(nPos); =xN= #
output.writeLong(fileSplitterFetch.nStartPos); {2KFD\i\
output.writeLong(fileSplitterFetch.nEndPos); %D=]ZV](
} zGlZ!t:
output.close(); L}k/9F.5
} K_&MoyJJ9f
catch(IOException e){e.printStackTrace ();} pdVQ*=c?M
catch(Exception e){e.printStackTrace ();} 3Ofc\
} m`A% p
&#w=7L3AW
:k=mzO<&
//读取保存的下载信息（文件指针位置） L^`}J7r
private void read_nPos() 19U]2D/z
{ $jzFc!rs
try{ hZ$t$3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dp5cDF}l
int nCount = input.readInt(); 0 p uY"[c
nStartPos = new long[nCount]; HIvZQQW|
nEndPos = new long[nCount]; P 7D!6q
for(int i=0;i<nStartPos.length;i++) F7}-!
{ _e<o7Y@_
nStartPos = input.readLong(); ^QXbJJ
nEndPos = input.readLong(); Dm0a.J v
} 1NLg _UBOK
input.close(); `ldz`yu6++
} ~/#1G.H
catch(IOException e){e.printStackTrace ();} mTDVlw0dh
catch(Exception e){e.printStackTrace ();} e@<?zS6
} Fke//- R
o>]`ac0b}Y
C(?blv-vM0
private void processErrorCode(int nErrorCode) 5FeFN)
{ @'2m$a
System.err.println("Error Code : " + nErrorCode); t*S." q
} hGTV;eU
Xl-e !
:l\V'=%9'@
//停止文件下载 J$ut_N):N
public void siteStop() *ZCn8m:-+
{ I:j3sy
bStop = true; ~mz%E
for(int i=0;i<nStartPos.length;i++) =r. >N\
fileSplitterFetch.splitterStop(); /F/;G*n
XP?rOOn
ssQ BSbx
} %yS3&Ju
} cntco@
//负责部分文件的抓取 H*I4xT@
**FileSplitterFetch.java b7:0#l$
*/ s][24)99
package NetFox; X@A1#z+s0]
Jf;?XP]z
){;02^tX
import java.io.*; }?8uH/+ZA
import java.net.*; Fj p.T;
:$3oFN*g
WgQBGch,!
public class FileSplitterFetch extends Thread { W8WXY_yJt
@* ust>7
e /K#>,
String sURL; //File URL J5M+FwZq
long nStartPos; //File Snippet Start Position ?\=/$Gt
long nEndPos; //File Snippet End Position >!6JKL~=
int nThreadID; //Thread's ID NZLAk~R;0
boolean bDownOver = false; //Downing is over cI0 ]}S
boolean bStop = false; //Stop identical d9^E.8p$
FileAccessI fileAccessI = null; //File Access interface r#i?j}F}
\_6OCVil
P\2M[Gu(Q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #;KsJb)N.
{ oA-:zz>wL
this.sURL = sURL; ~p1EF;4#
this.nStartPos = nStart; X@2-*so<
this.nEndPos = nEnd; k=ytuV\
nThreadID = id; S::=85[>z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G@ \Pi#1
} 32)tJ|m
J4$! 68
tfO#vw,@
public void run() YPDf Y<?v
{ i^`9syD
while(nStartPos < nEndPos && !bStop) V>-b`e
{ F'RUel_%
z`@^5_
7E$&2U^Js
try{ `6=-WEo
URL url = new URL(sURL); &]6)LFm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gxNL_(A
httpConnection.setRequestProperty("User-Agent","NetFox"); ~#K@ADYr
String sProperty = "bytes="+nStartPos+"-"; gk0.zz([
httpConnection.setRequestProperty("RANGE",sProperty); 6aft$A}XnD
Utility.log(sProperty); L71!J0@a#
nSx8E7 |V
-T@`hk`
InputStream input = httpConnection.getInputStream(); ~EiH-z4U
//logResponseHead(httpConnection); PyC0Q\$%
(?)7)5H
X@N$Z{
byte[] b = new byte[1024]; U\@A_ B
int nRead; I&yVx8aH}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Wzq>JNny
{ -Yi,_#3{
nStartPos += fileAccessI.write(b,0,nRead); OTWkUB{
//if(nThreadID == 1) ^Mkk@F&1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `TqSQg_l
} `(y(w-:W1
sUkm|K`#
6rti '
Utility.log("Thread " + nThreadID + " is over!"); )KSoq/
bDownOver = true; K+\nC)oG
//nPos = fileAccessI.write (b,0,nRead); AEirj /
} 3L>IX8_
catch(Exception e){e.printStackTrace ();} '_s}o<
} {Bvj"mL]j
} F?+3%>/A@
{BBw$m,o
RrrK*Fk8=
//打印回应的头信息 W[bmzvJ_X
public void logResponseHead(HttpURLConnection con) ;E;To\NCYF
{ E`\8TqO
for(int i=1;;i++) C2U~=q>>
{ % ~]xuP[
String header=con.getHeaderFieldKey(i); Pf_F59"
if(header!=null) 4p`XG1Pt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #EO1`9f48x
Utility.log(header+" : "+con.getHeaderField(header)); e9pOisZ;8
else l*aj#%ha
break; 'vV$]/wBF
} jF ^5}5U
} od<b!4k~s
cc=gCE
}3 m0AQ;K
public void splitterStop() [onqNp
{ BbOu/i|
bStop = true; or*HC&c7
} @`"AHt
%u\26[/
>QE{O.Z
} ^ZeJ[t&!#
NLd``=&
}-p[V$:S
/* gT+Bhr
**FileAccess.java GOy%^:Xd
*//文件访问(定位，写) 1MsWnSvzf
package NetFox; '!h/B;*(
import java.io.*; 4Cb9%Q0
,<,:8B
.\3`2
public class FileAccessI implements Serializable{ 'm=*u SJK
8OhDjWVJ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7k%T<;V
RandomAccessFile oSavedFile; 5ABhj*7
long nPos; fIC9WbiH-
P'Q$d+F,
m*0,s
public FileAccessI() throws IOException 4EP<tV
{ DC+wD Bp;
this("",0); SS|z*h Z
} ;oOv/3
v`[Eb27W.
N^0uit
public FileAccessI(String sName,long nPos) throws IOException i8X`HbmN
{ ;Q0bT`/X
oSavedFile = new RandomAccessFile(sName,"rw"); =1;=
this.nPos = nPos; 9W`Frx'h1
oSavedFile.seek(nPos); K ?$#ntp
} !<@J6??a}s
^nK7i[yF.k
gYop--\14]
public synchronized int write(byte[] b,int nStart,int nLen) ybdd;t}&1
{ Y$8JM
int n = -1; t%1^Li
try{ O;Y:uHf
oSavedFile.write(b,nStart,nLen); t=euE{c
n = nLen; dj6*6qX0'^
} 4pU>x$3$
catch(IOException e) D<{{ :7n
{ !G5a*8]
e.printStackTrace (); &F$:Q:* *
} &:B<Q$g#
B#%;Qc
V_n<?9^4
return n; X26
} f3*?MXxb16
K!AAGj`
/(C~~XP)
} 7sNw
qf)$$qi
vC;]jJb:
/* 'BMy8
**SiteInfoBean.java $K~LM8_CKy
*/ oT95^y\9
package NetFox; E N^Uki`
RuW!*LI
>?W[PQ5yx
public class SiteInfoBean { ~vdkFc(8B
2 -!L _W(
Ft JjY@#
private String sSiteURL; //Site's URL M&Y .;
private String sFilePath; //Saved File's Path tCF&OOI4`
private String sFileName; //Saved File's Name ~=r^3nZR/J
private int nSplitter; //Count of Splited Downloading File donw(_=
nx":"LFI
6qvp*35Cx
public SiteInfoBean() E9!N>0
{//nSplitter的缺省值为5 s=I'e/"7
//default value of nSplitter is 5 \g)Xt?w0Wo
this("","","",5); RH;:9_*F
} G`=r^$.3WB
9<CG s3\
"v*8_El
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L}{`h
{ \Xrw"\")j
sSiteURL= sURL; k5d\w@G"~
sFilePath = sPath; &.i^dO^}
sFileName = sName; IputF<p
this.nSplitter = nSpiltter; LS>G4 ]
=8G&3 R
BG2)v.CU
} Q'B6^%:<~
?@6b>='!
q(^Q3
public String getSSiteURL() ]Z<_ "F
{ c/W=$3
return sSiteURL; f5RE9%.#~
} u?+bW-D'd
Wa/g`}
e59dVFug.U
public void setSSiteURL(String value) P3tx|:gV
{ G1T^a>tj4
sSiteURL = value; TTNkr`
} 8 }'|]JK
3. WF}8
8U2dcx:G3
public String getSFilePath() `rY2up#%
{ )n7l'}o?+
return sFilePath; )YW<" $s
} 79J-)e9
92W&x'
DLE8+NV8
public void setSFilePath(String value) vy@rQC %9
{ WUdKLx%F
sFilePath = value; e=P
} JYqSL)Ta*t
nCg66-3A
EEy$w1ec
public String getSFileName() lEL78l.
{ 01a-{&
return sFileName; u8b2$D
} !,$i6gm
1nj(hg
`<\}FS`'
public void setSFileName(String value) beY=g7|
{ #PLEPB
sFileName = value; Sywu=b
} j{VGClb=T
{xcZ*m!B
7;`o( [N
public int getNSplitter() hi=XYC,
{ ;_kzcK!l
return nSplitter; &UHPX?x
} }H:F< z*
z|R,&~:
w [>;a.$
public void setNSplitter(int nCount) "pxzntY|
{ &YP#M|
nSplitter = nCount; USJ-e
} 2B~wHv
} lkIn%=Z
z5\;OLJS,
`XTh1Z\
/* Ths_CKwgWY
**Utility.java /RZR}
*/ fr6^nDY
package NetFox; _Yb_D/
~0"p*?^
iItcN;;7
public class Utility { q*jNH\|
c{ZY,C&<
BI[JATZG
public Utility() Q3W#`6jpF
{ aAvsb$
4wzlJ19E(
Qq-"Cg@-/
} YEu1#N
fpyz'
//线程睡眠 HY;o^drd
public static void sleep(int nSecond) cNpe_LvW
{ 4o:hyh
try{ wbyE;W
Thread.sleep(nSecond); '&O/g<Z}q
} ^(}585b
catch(Exception e) @*N)i?>
{ ]Hj<IvG
e.printStackTrace (); $Kj&)&M
} %b.UPS@I
} q}Z3?W
8{U-m0v
//日志 FxG7Pk+=
public static void log(String sMsg) 6Z?j AXGSq
{ @xsP5je]
System.err.println(sMsg); |xr%6 [Ff
} n@C~ev@%S
_;A $C(
~Aad9yyi
public static void log(int sMsg) _STB$cZ
{ 9&%fq)gS
System.err.println(sMsg); 6!iJ;1PeE
} C8N{l:1f]
} F,Xo|jjj
Hk_y/97OO
v}G]X Z8
/* nq}Q
**TestMethod.java `7aDEzmJ
*/ y]..=z_ql
package NetFox; >C WKH~
7DW]JK l
lor8@Qz
public class TestMethod { 3LR p2(A
~d{.ng 4K
f"#m=_Xm
public TestMethod() ? ]sM8Bd}
{ ///xx/weblogic60b2_win.exe R)?{]]v
try{ HJ?+A-n/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WzW-pV]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D*5hrkV9
SiteFileFetch fileFetch = new SiteFileFetch(bean); sGDV]~E
fileFetch.start(); j;yf8Nf
} !2CL1j0(
catch(Exception e){e.printStackTrace ();} Mkp/0|Q*
k?BJdg)xJ
qVjWV$j
} %HQ.|
FFhtj(hVgc
1 "TVRb
public static void main(String[] args) =6FUNvP#8
{ gV1[3dW
new TestMethod(); ?71+f{s
} (%CZ*L[9Z
} Ph&urxH@
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