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)); G0xk @SE
} )LKutN?tBy
for(int i=0;i<nEndPos.length-1;i++) Y{f;qbEQH'
{ $ [0
nEndPos = nStartPos[i+1]; -YJ7ne]
} 2PAotD4+I
nEndPos[nEndPos.length-1] = nFileLength; C[|jJ9VE,
} 6psK2d0
} x_s9DkX
[;83 IoU}
`>g: :
//启动子线程 q: ?6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cOxF.(L
for(int i=0;i<nStartPos.length;i++) gR?=z}`@p
{ !n@Yg2w
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ro$l/lXl8t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f*aYS
nStartPos,nEndPos,i); b:+.Y$%F-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); " q0lh
fileSplitterFetch.start(); j2k,)MHu!x
} ||0mfb
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SB:-zQ5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kOs_]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M(jSv
nEndPos = " + nFileLength); [qI, $ +
// fileSplitterFetch[nPos.length-1].start(); bmGIxBRq
o/)]z
"2o)1G
//等待子线程结束 ")i4w{_y
//int count = 0; pbl;n|
//是否结束while循环 E&7U |$
boolean breakWhile = false; l]uF!']f
%f*8JUE16
?qO_t;:0>
while(!bStop) X8GIRL)lJ
{ )8!""n~
write_nPos(); nulVQOj|
Utility.sleep(500); '[I?G6
breakWhile = true; Cevl#c5p>
W{*U#:Jx1
wC}anq>>
for(int i=0;i<nStartPos.length;i++) &)T5V
{ +%UfnbZ
if(!fileSplitterFetch.bDownOver) /hQTV!\u
{ 0h_9
breakWhile = false; ToTehVw
break; L(fOe3 v
} g\,pZ]0i
} >h(n8wTP
if(breakWhile) MRV4D<NQ
break; L 1H!o!*
pW2NrBq@w
b>er'U
//count++; 4%Z!*W*
//if(count>4) xVfAlN37(
// siteStop(); )R(kXz=M
} wzwEYZN(q
cGIxE[n'
@4#q
System.err.println("文件下载结束！"); 0r*E$|zZ
} onI%Jl sq
catch(Exception e){e.printStackTrace ();} iV58 m
} X3-pj<JLY
b8r?Dd"T8
'=Nb`n3%
//获得文件长度 mCb(B48]%X
public long getFileSize() o:W>7~$jr=
{ Ej~vp2
int nFileLength = -1; c>6dlWTqX
try{ G3 rTzMO
URL url = new URL(siteInfoBean.getSSiteURL()); nD@/,kw"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3"NO"+Q
httpConnection.setRequestProperty("User-Agent","NetFox"); ZX'q-JUv f
|-a5|3
MzM"r"u
int responseCode=httpConnection.getResponseCode(); o^&u?F9
if(responseCode>=400) -GCC
{ MxQhkY-=
processErrorCode(responseCode); Ye% e!
return -2; //-2 represent access is error ZVs]_`(+
} {p[{5k 0
9~n`6;R
c@7d4Jz
String sHeader; q^; SZ^yW5
O]3$$uI=QE
1LYz X;H1
for(int i=1;;i++) (H5nz':
{ lR5[UKr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,h,OUo]LIY
//Utility.log(in.readLine()); iO 9.SF0:
sHeader=httpConnection.getHeaderFieldKey(i); 6?$yBu9l
if(sHeader!=null) &W+lwEu
{ v3PtiKS
if(sHeader.equals("Content-Length")) BbsgZ4
{ 55q!2>Jh.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FjR/_GPo6
break; E6JfSH#
} 5.! OC5tO
} =1sGT;>
else fIe';a
break; -:cBVu-m
} `yF6-F
} .j^tFvN~L
catch(IOException e){e.printStackTrace ();} iZY4+ X
catch(Exception e){e.printStackTrace ();} i<@"+~n~GK
X .,Lmh
W>TG!R 5
Utility.log(nFileLength); 0,~||H{
~wYGTm=(n
x3DUz
return nFileLength; !z?&
} Voy1
6$/Z.8
Q\Wh]=}
//保存下载信息（文件指针位置） mxD]`F
private void write_nPos() 2iM]t&^<+
{ K|L&mL&8
try{ vT@*o=I
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;>hRj!
output.writeInt(nStartPos.length); )|3BS`
for(int i=0;i<nStartPos.length;i++) B|d-3\sn
{ dynkb901s
// output.writeLong(nPos); {=K);z
output.writeLong(fileSplitterFetch.nStartPos); &s6;2G&L$
output.writeLong(fileSplitterFetch.nEndPos); b'q ru~i
} X* 4C?v
output.close(); 43wm_4C!H
} xmVW6 ,<?
catch(IOException e){e.printStackTrace ();} H=lzW_(
catch(Exception e){e.printStackTrace ();} ?vt#M^Q
} T*o!#E.
=&T%Jm}
d?:KEi-<7
//读取保存的下载信息（文件指针位置） K@%o$S?>z_
private void read_nPos() La>fvm
{ CWBlDz
try{ .A6D&-&z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >0F)^W?
int nCount = input.readInt(); HuT4OGBFpC
nStartPos = new long[nCount]; R7\T.;8+
nEndPos = new long[nCount]; Cv[_N%3[
for(int i=0;i<nStartPos.length;i++) `D/<*e,#
{ gn//]|#H+
nStartPos = input.readLong(); =[JstiT?E
nEndPos = input.readLong(); lXpbAW
} uB=DC'lkg
input.close(); b~$8<\
} |j}D2q=
catch(IOException e){e.printStackTrace ();} b:WA}x V
catch(Exception e){e.printStackTrace ();} N\l|3~
} 5ENU}0W
h"0)g:\
.;\uh$c
private void processErrorCode(int nErrorCode) p=!12t
{ []lMv ZW
System.err.println("Error Code : " + nErrorCode); L"KKW c
} p!>5}f6
<-6f}wN
%$Dn);6=
//停止文件下载 nsL"'iQ
public void siteStop() b>h L*9
{ gmqA 5W~y
bStop = true; &]"Z x0t5%
for(int i=0;i<nStartPos.length;i++) 'XJqh|G
fileSplitterFetch.splitterStop(); LZtO Q__B)
&|-jU+r}B
?B+]Ex(\B,
} {x,d9I
} )\KU:_l
//负责部分文件的抓取 ~xLo0EV"
**FileSplitterFetch.java GIb,y,PDB
*/ ARUzEo gcf
package NetFox; R$h B9BK
#V{!|Y'
M!YGv
import java.io.*; bMq)[8,N
import java.net.*; 15z(hzU?#
IayF<y,8
!'eh@BU;
public class FileSplitterFetch extends Thread { S5BS![-QK
L35]'Jua
oeYUsnsbi
String sURL; //File URL a[VX)w_W{
long nStartPos; //File Snippet Start Position cYgd1
long nEndPos; //File Snippet End Position 9!_JV;2
int nThreadID; //Thread's ID r^7eK)XA_
boolean bDownOver = false; //Downing is over _z=ytt9D
boolean bStop = false; //Stop identical ."Kp6s`k
FileAccessI fileAccessI = null; //File Access interface gy1R.SN
9Y:Iha`$w
b_&:tE--]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k4d;4D?
{ w~C\5 i
this.sURL = sURL; -x{@D{Q%
this.nStartPos = nStart; MQe|\SMd
this.nEndPos = nEnd; .sjv"D"
nThreadID = id; @;G%7&ps
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C{:U<q
} q`VkA \
j[,XJ,5=
I5*<J n
public void run() uZTbJ3$$
{ 2KlVj]!7
while(nStartPos < nEndPos && !bStop) &^`[$LtYd
{ shD4";8*@
o@m7@$7
\[G"/]J
try{ ;qO3m-(d
URL url = new URL(sURL); c|@OD3w2lM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f?r{Q
httpConnection.setRequestProperty("User-Agent","NetFox"); AJ>$`=
String sProperty = "bytes="+nStartPos+"-"; ]VR79l
httpConnection.setRequestProperty("RANGE",sProperty); Wf3{z D~
Utility.log(sProperty); #_Zkke~{
QFK'r\3pU
wV\7
InputStream input = httpConnection.getInputStream(); Mtl`A'KQ/K
//logResponseHead(httpConnection); Q\W)}
foUBMl
HZ2f|Y|T
byte[] b = new byte[1024]; x~i\*Ox^
int nRead; DS+BX`i%#p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _FNW[V
{ xS(VgP&YGO
nStartPos += fileAccessI.write(b,0,nRead); d}aMdIF!e
//if(nThreadID == 1) }vU^gPH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7~r_nP_
} |{ =Jp<}s
I s|_
~z^49Ys:
Utility.log("Thread " + nThreadID + " is over!"); 1+"d-`'Z2O
bDownOver = true; qpQiMiB#g'
//nPos = fileAccessI.write (b,0,nRead); 9K;g\? 3
} .}GOHW)}
catch(Exception e){e.printStackTrace ();} *0vRVlYf
} KRX\<@
} !3<b#QAXRG
p1[|5r5Day
!<HF764@`
//打印回应的头信息 1g,Ofr
public void logResponseHead(HttpURLConnection con) B}P!WRNmln
{ fRxn,HyV
for(int i=1;;i++) 7|"l/s9,
{ Y3#8]Z_"}O
String header=con.getHeaderFieldKey(i); W9{i~.zo
if(header!=null) qu.AJ*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); M+M ;@3
Utility.log(header+" : "+con.getHeaderField(header)); k&M~yb
else XI:+EeM?
break; JC`;hY
} 2I3H?Lrx!m
} f*:N*cC
wy^mh.= UX
/l$fQ:l
public void splitterStop() bxPJ5oT
{ A>,kmU5
bStop = true; 3kh!dL3D
} k%8kt4\wn6
]yQqx*
v-8{mK`9\
} A8QUfg@uK~
O3?^P"C
Rqbz3h~
/* [?=DPE%
**FileAccess.java XZQ-Ig18
*//文件访问(定位，写) m^zD']
package NetFox; ;pS+S0U
import java.io.*; ?&!!(dWFH
txm6[Io
H]*B5Jv~
public class FileAccessI implements Serializable{ oGyoU#z#
}8ESp3~e_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _+)n}Se
RandomAccessFile oSavedFile; mKE'l'9A_
long nPos; RameaFX8
Unansk
$m-C6xC/
public FileAccessI() throws IOException C8i4z
{ \),zDO+
this("",0); V)4?y9xZv
} [vz2< genn
?)[=>Kp
Sj:c {jyJd
public FileAccessI(String sName,long nPos) throws IOException GY5JPl
{ xOr"3;^
oSavedFile = new RandomAccessFile(sName,"rw"); O>I%O^
this.nPos = nPos; +3M1^:
oSavedFile.seek(nPos); ?v-!`J>EF#
} {u0sbb(
@\:@_}Z`_}
PN=5ICT
public synchronized int write(byte[] b,int nStart,int nLen) c,]fw2
{ s0CDp"uJY
int n = -1; O'(D:D?
try{ s'd\"WaQV
oSavedFile.write(b,nStart,nLen); 6;@:/kl t
n = nLen; YE:5'@Z
} J0YNzC4
catch(IOException e) JaR!9GVN7
{ 1D2RhM%
e.printStackTrace (); uKTYb#E7
} .g7\+aiTUd
IGo5b-ds
0+)1KU)I
return n; @*uZ+$
} D51s)?
Z^Wv(:Nr
%tPy]{S..
} aI|X~b
KU Mk:5 c
1bDAi2 H
/* &LG|YvMY6
**SiteInfoBean.java eYn/F~5-
*/ w_;$ahsu~
package NetFox; mVN\
2|(lKFkQ
"\]]?&
public class SiteInfoBean { eht>4)
uJ fXe
knfmJUT
private String sSiteURL; //Site's URL JV8*;n%}-
private String sFilePath; //Saved File's Path g&Uu~;jq]
private String sFileName; //Saved File's Name sPl3JP&s
private int nSplitter; //Count of Splited Downloading File {qU;>;(
h0A%KL
#;+SAoN
public SiteInfoBean() !w0=&/Y{R
{//nSplitter的缺省值为5 U7e2NES
//default value of nSplitter is 5 'Q=(1a11
this("","","",5); b/\l\\$-
} 3<[q>7X
bj_/
Z.rhM[*+0C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >z%WW&Z'
{ ~BE=z:
sSiteURL= sURL; eLV[U
sFilePath = sPath; ytb1hFs
sFileName = sName; S)'&+HamI
this.nSplitter = nSpiltter; ELg$tc
kbbHa_;aqV
aZ|S$-}
} ?(}~[
h&!$ `)
^&c &5S}
public String getSSiteURL() ~fzuz'"^
{ TN08,:k
return sSiteURL; pX$X8z%
} F}@]Lq+
)jjaY1E
H;DjM;be
public void setSSiteURL(String value) 7h:EU7
{ ^gY'^2bzxu
sSiteURL = value; 5`i+aH(
} EY c)v6[
tWQ$`<h
6(Ntt
public String getSFilePath() nQg_1+
{ \NKw,`/
return sFilePath; Q)8I(*
} H:WuMwD4
{h.j6
dYlVJ_0Zr
public void setSFilePath(String value) dl`{:ZR S
{ 9A|9:OdG1
sFilePath = value; )t:8;;W@Ir
} 2r]o>X
:2XX~|
sv#b5,>9
public String getSFileName() s"2+H}u
{ g0IvcA
return sFileName; VCIV*5 P
} NQcg}y
PIoBKCJ
^V]IPGV
public void setSFileName(String value) A^zd:h-
{ Mp[2Auf
sFileName = value; e)87 & 7
} : &~LPmJ
$U)nrni
}gE^HH'
public int getNSplitter() <7gv<N6BQf
{ [8Z !dj
return nSplitter; $'::51
} yb0Mn*X+ N
dVn_+1\L
e5'U[bQm
public void setNSplitter(int nCount) &;<'AF
{ QHnC(b
nSplitter = nCount; j6L(U~%
} O.8k [Ht
} 1?Tj
8]bLp
h2i1w^f
/* #)iPvV'
**Utility.java CT'#~~QB
*/ XPnHi@x
package NetFox; !!cN4X
[h8macx
vY,D02EMw
public class Utility { \]dvwN3x
Z.s0ddMs
(CJx Y(1K
public Utility() +%K~HYN
{ o*oFCR]j
.kgt?r
X!@ Y,
} "M^mJl&*b
MN:LL <
//线程睡眠 E Q:6R|L
public static void sleep(int nSecond) |=V~CQ]
{ y'non0P.
try{ >Pvz5Hf/wW
Thread.sleep(nSecond); ;krIuk-
} h R6Pj"@0
catch(Exception e) Ry?f; s
{ iqN?'8
e.printStackTrace (); ^ohIJcI-
} ksUF(lYk
} Q^* 33
.>LJ(Sx9b
//日志 Z'|k M!
public static void log(String sMsg) dfZ`M^NU
{ s .+`"rK
System.err.println(sMsg); vI,T1%llu
} Wr'1Y7z
ViG>gMGv
s=556
public static void log(int sMsg) b #Llu$
{ iJCv+p_f
System.err.println(sMsg); jvo^I$|2h
} o8NRu7@?
} 9n"MNedqH
jX^_(Kg
imKMPO=
/* !fjB oK+
**TestMethod.java Q{yjIy/b
*/ 91nw1c!
package NetFox; 9`M7 -{
sa"}9IE*8
\0&F'V
public class TestMethod { MIh\z7gW
z<.?8bd
)lq+Gv[%F
public TestMethod() q1m{G1W n
{ ///xx/weblogic60b2_win.exe ^`Hb7A(
try{ kv;P2:"|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #7/39zTK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cH+ ~|3
SiteFileFetch fileFetch = new SiteFileFetch(bean); hML-zZ
fileFetch.start(); 0Q)YZ2
} k|U2Mp
catch(Exception e){e.printStackTrace ();} H6U5-
DKkilqVM
:T<5Tq*+x
} hVui.]
.N`*jT
T)',}=
public static void main(String[] args) Ba**S8{/`
{ :\y' ?d- Q
new TestMethod(); JV_VM{w{K
} f[ia0w5 m
} 4yjIR?
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