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)); Sp`l>BL
} FO{=^I5YA
for(int i=0;i<nEndPos.length-1;i++) ycA<l"
{ PKm|?kn{0(
nEndPos = nStartPos[i+1]; hmy%X`%j
} r )|3MUj
nEndPos[nEndPos.length-1] = nFileLength; l#)X/(?;
} cNll??j
} `oRyw6Sko
h~dQ5%
#w$Y1bjn
//启动子线程 {Jr1K,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *k?:k78L
for(int i=0;i<nStartPos.length;i++) E)b$;'
{ R2bqhSlF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _&KqmQ8$7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Im]@#X
nStartPos,nEndPos,i); ]8G 'R-8}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WtSs:D
fileSplitterFetch.start(); K#"=*p,
} r>mBe;[TX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u6iW1,#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Dy08.Sss
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b,!C8rJ
nEndPos = " + nFileLength); 1{uxpYAP=
// fileSplitterFetch[nPos.length-1].start(); kG^76dAQL
n ]%2Kx
B|`?hw@g+
//等待子线程结束 5epI'D
//int count = 0; a@}.96lStD
//是否结束while循环 %VHy?!/
boolean breakWhile = false; (leX` SN0u
Iix,}kzss
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while(!bStop) Bfb~<rs[
{ ct+F\:e
write_nPos(); R'c*CLaiE
Utility.sleep(500); q~{) {t;
breakWhile = true; %G?@Hye3
*)^6'4=
Y,L`WeQY.
for(int i=0;i<nStartPos.length;i++) )"x6V""Rb
{ c~|(j \FI
if(!fileSplitterFetch.bDownOver) 8t+eu O
{ ;`AB-
breakWhile = false; +IZ=E >a
break; X4!93
} UB~K/r`.|
} zCs34=3D[
if(breakWhile) HcRw9,I'
break; bWyimr&B
FvT&nb{
(Tx_`rO4VY
//count++; 0aT:Gy;
//if(count>4) q` S ~w
// siteStop(); Y:*% [\R
} vG|!d+
@f[-
+.cpZqWn3
System.err.println("文件下载结束！"); i?L=8+9f
} QE 4
catch(Exception e){e.printStackTrace ();} /*C!]Z>.
} UiU/p
C T~6T&'
T!/o^0w
//获得文件长度 "LlpZtw
public long getFileSize() NKY|Z\
{ n6Oz[7M
int nFileLength = -1; B>{%$@4
try{ (l5p_x
URL url = new URL(siteInfoBean.getSSiteURL()); ^^q&VL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %:26v
httpConnection.setRequestProperty("User-Agent","NetFox"); d+n2 c`i
{lK2yi
HDm]njF%qQ
int responseCode=httpConnection.getResponseCode(); 2gWR2 H@
if(responseCode>=400) lHiWzt u
{ ~[H8R|j "
processErrorCode(responseCode); .Ys e/oEo
return -2; //-2 represent access is error &%J{uRp
} e;i 6C%DB
v^A+LZ*d
QQ?t^ptv
String sHeader; tPyk^NJ;
pPL=(9d
/gAT@Vx
for(int i=1;;i++) SIK:0>yK"
{ 0E\#!L
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); pq*e0uW
//Utility.log(in.readLine()); LhG\)>Y%
sHeader=httpConnection.getHeaderFieldKey(i); {S0-y
if(sHeader!=null) z ]f(lwo{
{ #-|fdcb
if(sHeader.equals("Content-Length")) 1dvP2E
{ `wa;@p+j8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *eg0^ByeD
break; "DN,1Q lCp
} 8Z!%rS
} ,ye}p1M
else %g:Q?
break; c5p,~z_Dtu
} (]w6q&,
} tE%g)hL-
catch(IOException e){e.printStackTrace ();} <F^9ML+'
catch(Exception e){e.printStackTrace ();} 2n.HmS
NX\AQVy9
,nf}4
Utility.log(nFileLength); ;R=n<=Axa
re*Zs}(N\
sOqFEvzo1%
return nFileLength; ^i@anbH
} -9vNV:c
B/X$ZQ0
RUY7Y?
//保存下载信息（文件指针位置） kq| !{_
private void write_nPos() G#[A'tbKk
{ yjT>bu]
try{ DN:| s+Lz
output = new DataOutputStream(new FileOutputStream(tmpFile)); AL":j6!OQ
output.writeInt(nStartPos.length); 20I`F>-*
for(int i=0;i<nStartPos.length;i++) &G2&OFAr]q
{ 4eWv).
// output.writeLong(nPos); gWgp:;Me
output.writeLong(fileSplitterFetch.nStartPos); Kyx9_2
output.writeLong(fileSplitterFetch.nEndPos); F'MX9P
} 4prJ!k
output.close(); iw#~xel<ez
} !h1:AW_iz
catch(IOException e){e.printStackTrace ();} Bq$IBAot
catch(Exception e){e.printStackTrace ();} #^$_/Q#C
} Oj-\
?Uq"zq
;6@sC[
//读取保存的下载信息（文件指针位置） HGAi2+&
private void read_nPos() LqYyIbsvf
{ Tdh(J",d
try{ S ,F[74K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?OW!D?
int nCount = input.readInt(); g}!{_z
nStartPos = new long[nCount]; Uha.8
nEndPos = new long[nCount]; +TbAtkEF*
for(int i=0;i<nStartPos.length;i++) XQ~Xls%]
{ z~2{`pET
nStartPos = input.readLong(); W=HvMD
nEndPos = input.readLong(); lU 62$2
} uxyj6(
input.close(); NzAh3k
} $'KQP8M+
catch(IOException e){e.printStackTrace ();} OxDqLX
catch(Exception e){e.printStackTrace ();} e6MBy\*n
} nA0%M1a
.@fA_8
X$KTsG*
private void processErrorCode(int nErrorCode) ZBDF>u@
{ JPF6zzl)
System.err.println("Error Code : " + nErrorCode); aX1b(h2
} u<8b5An;
Mf14> `<`
wU|@fm"
//停止文件下载 +D5gbxZX
public void siteStop() A|LO!P,w
{ 3Ewdu
bStop = true; w71YA#cg
for(int i=0;i<nStartPos.length;i++) %|e)s_%XE
fileSplitterFetch.splitterStop(); -E1-(TS
d<d3j9u(#
CNb(\]
} "dP-e
} ,c:NdY(,)
//负责部分文件的抓取 tC|?Kl7
**FileSplitterFetch.java ]y.V#,6e
*/ (o*YGYC
package NetFox; \dCGu~bT
#f"eZAQ {
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import java.io.*; ~;9n6U
import java.net.*; {@CQ (
M6&=-
0U~$u
public class FileSplitterFetch extends Thread { Tr_gc~
$F^VtCx2&
Ho&:Zs
String sURL; //File URL f2[R2sto@
long nStartPos; //File Snippet Start Position {ol7*%u
long nEndPos; //File Snippet End Position Uj;JN}k
int nThreadID; //Thread's ID 7LU^Xm8
boolean bDownOver = false; //Downing is over $M)SsD~
boolean bStop = false; //Stop identical !#pc@(rE
FileAccessI fileAccessI = null; //File Access interface ;@=3 @v
pMT7/y-
QL8C!&=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7Tk//By7
{ sJx_X8
this.sURL = sURL; 9HO9>^
this.nStartPos = nStart; {[#)Q.2
this.nEndPos = nEnd; |` ~ioF
nThreadID = id; O`0r'&n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /i8OyRpSyk
} r'Wf4p^Xd
Hk;;+'-
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public void run() [3bPoAr\
{ 7zCJ3p
while(nStartPos < nEndPos && !bStop) 2`*w*
{ ~\(c;J*Ir
iXy1{=BDv
FbroI>"e
try{ ]fzXrN_
URL url = new URL(sURL); UstUPO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }| MX=:@*
httpConnection.setRequestProperty("User-Agent","NetFox"); f|VCibI
String sProperty = "bytes="+nStartPos+"-"; N#Rb8&G)b
httpConnection.setRequestProperty("RANGE",sProperty); EA(4xj&:U
Utility.log(sProperty); 1SztN3'q
}?,YE5~
Bk\Y v0
InputStream input = httpConnection.getInputStream(); Wz.iDRFl
//logResponseHead(httpConnection); o3hgkoF
;Tr,BfV|Bf
F}{%*EJ
byte[] b = new byte[1024]; QP.Lq}
int nRead; ymxA<bICS8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BW)-F (v
{ hhaiHi!$
nStartPos += fileAccessI.write(b,0,nRead); ]?+i6 [6U
//if(nThreadID == 1) X PyDZk/m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Qu[QcB{ro-
} Fn.JtIu
;+XrCy!.)L
ss%,
Utility.log("Thread " + nThreadID + " is over!"); pWKE`x^
bDownOver = true; WfaMu| L
//nPos = fileAccessI.write (b,0,nRead); }(8>&
} g>h/|bw4
catch(Exception e){e.printStackTrace ();} 2|^@=.4\
} 7qyPI
} z*h:Nt%.
2j8GJU/L
te(H6c#0
//打印回应的头信息 uCr& `
public void logResponseHead(HttpURLConnection con) BJwuN
{ _M/N_Fm
for(int i=1;;i++) #?w07/~L
{ LH2B*8=^2
String header=con.getHeaderFieldKey(i); I+H~ 5zq.
if(header!=null) sR1_L/.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5?;<^J
Utility.log(header+" : "+con.getHeaderField(header)); 7tlK'j'
else z(LR!hr
break; KxK,en4)+
} cZ_)'0
} exJc[G&t(
^%,{R},s
YA$YT8iMe
public void splitterStop() ,5v'hG
{ =xm7i#1
bStop = true; IWu=z!mO
} A]!0Z:{h%
9oJM?&i
<b H*f w
} nC p/.]Y*
'Wnh1|z
w@^J.7h^
/* *@''OyL
**FileAccess.java Mc.{I"c@
*//文件访问(定位，写) |gI>Sp%Fu
package NetFox; @$r[$D v
import java.io.*; sMGo1pG(
N_NN0
I}bu
public class FileAccessI implements Serializable{ %3qjgyLZ|
_ +DL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FzX ;~CA
RandomAccessFile oSavedFile; >[aR8J/U
long nPos; ?pZU'5le`
5zBA]1PY
GP c B(
public FileAccessI() throws IOException Kg';[G\
{ (|<S%?}J
this("",0); fX`u"`o5
} AuQ|CXG-\
4Y?2u
R 9`[C
public FileAccessI(String sName,long nPos) throws IOException zN!W_2W*
{ + )Qu,%2
oSavedFile = new RandomAccessFile(sName,"rw"); e-y$&[
this.nPos = nPos; ?YR;o4
oSavedFile.seek(nPos); 9JP:wE~y
} sPi
K+vD&Z^
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public synchronized int write(byte[] b,int nStart,int nLen) HNS^:XR
{ P}8hK
int n = -1; *fc8M(]&d
try{ yZ6WbI8n
oSavedFile.write(b,nStart,nLen); AVQcD`V3B
n = nLen; UCcr>
} ,;}
catch(IOException e) w{DU<e:
{ "'[M~Js
e.printStackTrace (); s`=| D'G(=
} 8<;.
zK~8@{l}_"
3R<r[3WP
return n; w3,KqF
} )1Bz0:
C`[2B0
C{/U;Ie-b
} n~6$CQ5dF(
u!D?^:u=)
a?+C]u?_D
/* ;>Z+b#C[
**SiteInfoBean.java y_Lnk=Q ^
*/ n)X%&_
package NetFox; P 2_!(FZ<l
NW6;7nWb
gS<p~LPf
public class SiteInfoBean { tRU/[?!
>97YK =
[]@@
private String sSiteURL; //Site's URL y`zdI_!7
private String sFilePath; //Saved File's Path u W,J5!
private String sFileName; //Saved File's Name sZ=!*tb-
private int nSplitter; //Count of Splited Downloading File 0x~+=GUN
o(e(|k {
]~]TZb
public SiteInfoBean() mH$`)i8
{//nSplitter的缺省值为5 h81giY]
//default value of nSplitter is 5 VgXT4gO!
this("","","",5); (nLzWvN
} xMk>r1Ud
c\ZI 5&4jT
X[?fU&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1sg:8AA
{ cZN<}n+q
sSiteURL= sURL; h!dij^bD
sFilePath = sPath; 17'd~-lE
sFileName = sName; ~s&r.6DW
this.nSplitter = nSpiltter; SYi!%
X$;x2mz nM
]Y]]X[@
} !QVhP+l'H
).jQ+XE'>
!:\0}w$-
public String getSSiteURL() Vyi.:lL _8
{ w%`S>+kX&
return sSiteURL; spP[S"gI
} | t:UpP
$&.(7F^D
3_wR2AU~
public void setSSiteURL(String value) EFDmNud`Q
{ [@qjy*5p
sSiteURL = value; $A~aNI
} -`5]%.E&8
xT&/xZLT
[gUD +
public String getSFilePath() VM5'd
{ ugN%8N
return sFilePath; 02EX_tt),
} Yz2N(g[
=A,T:!}'
S}Wj.l+F
public void setSFilePath(String value) tOVTHx3E]
{ ^(
sFilePath = value; $'CS/U`E}
} rx| ,DI
4j0;okQWV'
8cZ[Kl%
public String getSFileName() FP&Ykx~
{ F\&wFA'J
return sFileName; N>EMVUVS
} ,k.")
j{FRD8]V
u `ww
public void setSFileName(String value) l$!ExXEZO;
{ V"8Go;[
sFileName = value; U4dfO=
} M3UC9t9]
J0k!&d8
Tr>_R%bK
public int getNSplitter() O=}
{ zytW3sTZA
return nSplitter; GBZu<t/
} m==DBh
z+oy#p6+F.
$27OrXQ|
public void setNSplitter(int nCount) *lZ V3F
{ rgXX,+cO
nSplitter = nCount; q}jh>`d
} V&j]*)
} VXk[p
lrkgsv6
LsGO~EiJ
/* 0ie)$fi
**Utility.java Vq#0MY)2gS
*/ a"4X7 D+
package NetFox; 21<Sfsc$
C+!=C{@7di
Cs"ivET
public class Utility { .(p_YjIA
P;XA|`&
kn$SG
public Utility() d$\n@}8eZp
{ 1M)88&
)X*_oH=
1)}hzA
} qldm"Ul
7^.g\Kt?
//线程睡眠 SsMs#C8u%
public static void sleep(int nSecond) ,,j>2Ts
{ /w6'tut
try{ Xeja\5zB
Thread.sleep(nSecond); zGd[sjL
} 3`3my=
catch(Exception e) qMVuBv
{ TRgj`FG
e.printStackTrace (); lM#/F\
} to_dNJbv
} w"kBAi&
X/%!p<}:'
//日志 :zIB3nT^
public static void log(String sMsg) JC$_Pg!
{ |w~*p N0
System.err.println(sMsg); (:H4
} oKkDG|IE
wE9z@\z]
vfDX~_N
public static void log(int sMsg) Iza#v0
{ yHf^6|$8
System.err.println(sMsg); {J)gS
} 6R3/"&P(/#
} Y*jkUQ
C@XnV=J
4%yeEc;z
/* R Ee~\n+P^
**TestMethod.java BUI#y `J
*/ ~t*_
package NetFox; _Nz?fJ:$@
y9i+EV
X+\=dhn69
public class TestMethod { `} 'o2oZnG
%dd B$(
Xa'b@*o&
public TestMethod() &F0>V o
{ ///xx/weblogic60b2_win.exe =`MQKh,
try{ |gk"~D
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LDo~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?*q-u9s9
SiteFileFetch fileFetch = new SiteFileFetch(bean); rV%;d[LB
fileFetch.start(); MnY}U",
} './qBJ
catch(Exception e){e.printStackTrace ();} <gvgr4@^yR
~O/B
? R[GSS1
} }*P;kV
ucLh|}jJ5
R6GlQ G
public static void main(String[] args) bV)h\:oC
{ ey>tUmt6?
new TestMethod(); L?(1 [jB4G
} cE,,9M@^
} |BbrB[+ v[
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