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)); 0[);v/@Ho
} WI](a8bm
for(int i=0;i<nEndPos.length-1;i++) E3_EXz9h
{ 1LT)%_d@
nEndPos = nStartPos[i+1]; n]6xrsE
} -Ufd+(
nEndPos[nEndPos.length-1] = nFileLength; t 0nGZ%`
} R%8nR6iG"
} IAhyGD{b
2 os&d|
ZTMzL%i
//启动子线程 EX=+TOkAf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6=MejT
for(int i=0;i<nStartPos.length;i++) dB^J}_wp
{ *N[.']#n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O&E1(M|*>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y>wpla[kUq
nStartPos,nEndPos,i); o5i?|HJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ShF ][v1L
fileSplitterFetch.start(); vA;ml$
} ZRsDn
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $9M>B<]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); P\*-n"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S2;{)"mS
nEndPos = " + nFileLength); ,BOB &u
// fileSplitterFetch[nPos.length-1].start(); ~}$:iyJV(>
J0C<Qb[
V-O49
//等待子线程结束 'nBJ[$2^
//int count = 0; IP-CN
//是否结束while循环 D0us<9q
boolean breakWhile = false; =@G#c5H*
M!;H3*
2RT9Q!BX{
while(!bStop) Pb+oV
{ "7l p|0I
write_nPos(); * j:
Utility.sleep(500); ubj ~ULA
breakWhile = true; Czid"Ih-
*x)WF;(]g
M5: f^
for(int i=0;i<nStartPos.length;i++) WK:~2m&y
{ lWd)(9Kj
if(!fileSplitterFetch.bDownOver) =}Bq"m
{ DTlM}
breakWhile = false; L7wl3zG
break; =LZj6'
} $_@~t$
} --Dw8FR9
if(breakWhile) 0A9x9l9Wd
break; }sd-X`lZ
<@A/`3_O)
L!3{ASIN0
//count++; cx1U6A+
//if(count>4) mhnD1}9,Ih
// siteStop(); J,4]du$
} |.*),t3 (w
pvDr&n9
HJ !)D~M{
System.err.println("文件下载结束！"); [qIi_(%o
} ;]i&AAbj
catch(Exception e){e.printStackTrace ();} RR75ke[Hs
} [WRs1$5
ryW1OV6?_0
*;,=x<
//获得文件长度 !})/x~~e
public long getFileSize() i>7f9D7
{ gTH1FR8$y
int nFileLength = -1; T9*\ITA
try{ l:z:tJ#(
URL url = new URL(siteInfoBean.getSSiteURL()); UH%oGp$ykX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e ! 6SJ7xC
httpConnection.setRequestProperty("User-Agent","NetFox"); F,11 \j
`[jQn;
$io-<Z#Q
int responseCode=httpConnection.getResponseCode(); TEh]-x`
if(responseCode>=400) nAoGG0$5
{ \&&kUpI
processErrorCode(responseCode); {YcVeCq+N
return -2; //-2 represent access is error x98LOO
} ]^3_eHa^d
\Y Cj/tG8
zb?wlfT
String sHeader; F$ZWQ9&5U0
f"k?Ix\ e
lqF{Y<l
for(int i=1;;i++) $P866F
{ awHfd5nRS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /A9Mv%zjk
//Utility.log(in.readLine()); fB3O zff
sHeader=httpConnection.getHeaderFieldKey(i); X']>b
if(sHeader!=null) l^uP?l"
{ PJAE~|a
if(sHeader.equals("Content-Length")) j<szQ%tJlI
{ prlB9,3|C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QTz{ZNi!
break; U4 m[@wF
} ;}A#ws_CD_
} .sbU-_ij@U
else 9(|[okB
break; +y6|Nq
} tmRD$O%:
} ojs&W]r0Z
catch(IOException e){e.printStackTrace ();} q&<#)#+
catch(Exception e){e.printStackTrace ();} /quf'CV}
dsR{ P,!
H'q&1^w)
Utility.log(nFileLength); $a15 8
6x]|IWvW
?uU0NKZA
return nFileLength; \S=!la_T@m
} Pl}}!<!<z
mIFS/C
7v?tSob:b
//保存下载信息（文件指针位置） S82NU2L
private void write_nPos() ]WWre},
{ !Ya +
try{ }h+a8@
output = new DataOutputStream(new FileOutputStream(tmpFile)); D4 {gt\V
output.writeInt(nStartPos.length); :54|Z5h|
for(int i=0;i<nStartPos.length;i++) #7lkj:j4
{ 3a!/EP
// output.writeLong(nPos); rHT8a^MO
output.writeLong(fileSplitterFetch.nStartPos); 66p_d'U
output.writeLong(fileSplitterFetch.nEndPos); D'fP2?3FK
} o4w+)hh
output.close(); Qc[[@=S%
} Yo| H`m,
catch(IOException e){e.printStackTrace ();} IH\k_Yf#u
catch(Exception e){e.printStackTrace ();} iBp 71x65
} )P|%=laE8
{)4Vv`n
F#X\}MvEU
//读取保存的下载信息（文件指针位置） K ANE"M
private void read_nPos() .Z%7+[
{ e&;c^Z
try{ +FY-r[_~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Pk8L-[&v
int nCount = input.readInt(); 2*K0~ b`
nStartPos = new long[nCount]; @]3(l
nEndPos = new long[nCount]; nXi6Q+YI
for(int i=0;i<nStartPos.length;i++) <e/O"6='Z
{ AU87cqq
nStartPos = input.readLong(); II>X6
nEndPos = input.readLong(); Y0s^9?*
} y^;qT_)#
input.close(); Qi=rhN`
} M?[lpH3
catch(IOException e){e.printStackTrace ();} R&ou4Y:DG
catch(Exception e){e.printStackTrace ();} lmH!I)5
} 7c %@2
&sS k~:
OUI}jJw+
private void processErrorCode(int nErrorCode) ry~3YYEMI0
{ <RGRvv
System.err.println("Error Code : " + nErrorCode); DOhXb
} 9?,n+
F<V zVEx
}{K)5k@
//停止文件下载 @'C)ss=kj
public void siteStop() Z]w_2- -
{ cb'8Li8,j
bStop = true; wTIf#y1=9
for(int i=0;i<nStartPos.length;i++) ZmmuP/~2K
fileSplitterFetch.splitterStop(); 6b<t|zb
?ZDx9*f
?a}eRA7
} xZ;';}&pj
} X\1D[n:
//负责部分文件的抓取 ngm7Vs
**FileSplitterFetch.java {F@;45)o
*/ zh/+1
package NetFox; Bj@&c>
}Ecm
ARQ1H0_B
import java.io.*; 8$G$Rdn
import java.net.*; i3e|j(Gs4
*,'"\n
t8?+yG;
public class FileSplitterFetch extends Thread { []dRDe;#
ioa 1n=j
i w m7M
String sURL; //File URL A%Bz52yg
long nStartPos; //File Snippet Start Position 'kx{0J?
long nEndPos; //File Snippet End Position !%Z1"FDm/
int nThreadID; //Thread's ID /f#rN_4
boolean bDownOver = false; //Downing is over U]R7=
boolean bStop = false; //Stop identical \2NiI]t]
FileAccessI fileAccessI = null; //File Access interface E"L'm0i[[
:-6_X<
@F3d9t-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .S?,%4v%%
{ |?g2k:fzB7
this.sURL = sURL; BwEL\*$g
this.nStartPos = nStart; 8\I(a]kM`
this.nEndPos = nEnd; N#[/h96F
nThreadID = id; JBoo7a1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <n6/np!
} U{ahA
}:jXl!:V
7kJ,;30)
public void run() UI8M<
{ uk\GAm@O
while(nStartPos < nEndPos && !bStop) 4tu2%Og)?
{ G 8NSBaZe
l;|1C[V
eGguq~s`
try{ JT_#>',
URL url = new URL(sURL); @l;f';+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O]~p)E
httpConnection.setRequestProperty("User-Agent","NetFox"); x`o_&09;CG
String sProperty = "bytes="+nStartPos+"-"; ~z< ? Wh
httpConnection.setRequestProperty("RANGE",sProperty); SnXYq7`t
Utility.log(sProperty); .0a$E`V=D
DH9?~|
#vDe/o+=
InputStream input = httpConnection.getInputStream(); Q7DkhKT
//logResponseHead(httpConnection); CX1'B0=\r
'E7|L@X"r
\7/xb{z|
byte[] b = new byte[1024]; +:Y6O'h.
int nRead; .d8~]@U!<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }RyYzm2
{ 5,mb]v0k
nStartPos += fileAccessI.write(b,0,nRead); sF<4uy
//if(nThreadID == 1) zF{z_c#3@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yXEC@#?|
} nKHyq\
?VzST }
z!F?#L5
Utility.log("Thread " + nThreadID + " is over!"); t;4{l`dk
bDownOver = true; |bBYJ
//nPos = fileAccessI.write (b,0,nRead); ZAiQofQ:2
} leyX: +
catch(Exception e){e.printStackTrace ();} &j>`H:
} P"xP%zqo
} =)T5Y,+rJ
rsc8lSjH
c3Mql+@
//打印回应的头信息 e{?~m6
public void logResponseHead(HttpURLConnection con) 5q8bM.k\7N
{ BGA.8qWR4
for(int i=1;;i++) \?GMtM,
{ 3-Ti'xM
String header=con.getHeaderFieldKey(i); .IYE"0)wJ
if(header!=null) '7E?|B0],
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^ 5UIbA(
Utility.log(header+" : "+con.getHeaderField(header)); Qb SX'mx<
else c5t?S@b
break; "0]i4d1l
} V= .'Db2D
} Uq[NOJC
H>W A?4
p oNQ<ijK
public void splitterStop() zx\?cF
{ YxsWY7J
bStop = true; g@S"!9[;U
} G_X'd
hx:x5L>
^c-1wV`/
} K\;b3
~A6QX8a
M~wJe@bc
/* Dpof~o,f
**FileAccess.java T"dEa-O
*//文件访问(定位，写) paiF ah
package NetFox; ,c7 8O8|
import java.io.*; rt."P20T
Z!ub`coV[
;up89a-,9
public class FileAccessI implements Serializable{ Z,Q)\W<'-
h"q`gj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q,+d\-+
RandomAccessFile oSavedFile; _STN^
long nPos; P/0n) Q
j4Lf6aUOX
mF#{"
public FileAccessI() throws IOException ~xzRx$vU
{ 6{1c S
this("",0); \f%jN1z
} ~I!7]i]"*?
nKV1F0-
N|8TE7- F|
public FileAccessI(String sName,long nPos) throws IOException O[q {y
{ dx:],VB
oSavedFile = new RandomAccessFile(sName,"rw"); 6R#f 8
this.nPos = nPos; -x7b6o>$
oSavedFile.seek(nPos); [['un\~r~
} s_VP(Fe@K
;JDxl-~
Au:Q4x.
public synchronized int write(byte[] b,int nStart,int nLen) N0/DPZX7
{ Joe k4t&0<
int n = -1; 5H>[@_u+:
try{ l*/I ;a$
oSavedFile.write(b,nStart,nLen); n Hy|
n = nLen; {3!v<CY'
} `|Tr"xavf
catch(IOException e) k%JwS_F
{ q]<cn2
e.printStackTrace (); rT5dv3^MW!
} >*dqFZF
t|d9EC]c(
ZOfyy E
return n; nIKh<ws4z
} ^P\(IDJCo
?r#e
jsc1B
} .J'}qkz~
X >C*(/a
fY$M**/,
/* yp_:]RE
**SiteInfoBean.java (B]rINY|
*/ k)dLJ<EM
package NetFox; OZs^c2 W
t-i;
Pf-k"7y
public class SiteInfoBean { X.bNU
fD]}&xc
)<t5' +d%
private String sSiteURL; //Site's URL GR Rv0M
private String sFilePath; //Saved File's Path -T`rk~A9A
private String sFileName; //Saved File's Name vG69z&
private int nSplitter; //Count of Splited Downloading File pjWqI6,
{Jwh .bJ
( {5LB4
public SiteInfoBean() 9}jF]P*Q
{//nSplitter的缺省值为5 [C9->`(`
//default value of nSplitter is 5 ON\_9\kv
this("","","",5); 'eZUNX
} AWc7TW
%sbDH
@|idlIey
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "i(k8+iK
{ ab: yH ')
sSiteURL= sURL; 2D>WIOX
sFilePath = sPath; 5iwJdm
sFileName = sName; L"P$LEk
this.nSplitter = nSpiltter; g%Sl+gWdJ
V*2uW2\}
D:/^TEib
} VkZrb2]v
>/Gz*.
db'Jl^
public String getSSiteURL() Zchs/C 9{
{ 2X!O '
return sSiteURL; {'NdN+_C
} K}L-$B*i
bb`GV
{.K>9#^m
public void setSSiteURL(String value) 'C)`j{CS
{ Om,+59ua*
sSiteURL = value; !MOVv\@O
} hjtkq.@
d dkh*[
67wY_\m9I
public String getSFilePath() ,|<2wn#q
{ -1;BwlL
return sFilePath; !X[b 4p
} 6*J`2U9Q
3pl/kT.\
P4-`<i]!S
public void setSFilePath(String value) q;3.pRw(
{ N0,wT6.
sFilePath = value; */;[ -9
} F#*vJb)
*$1M=$
u^8:/~8K
public String getSFileName() Y!N*J
{ M{<cqxY
return sFileName; (sHqzWh
} y0k*iS e
)7l+\t
e)]9u$x
public void setSFileName(String value) k7z;^:
{ *NHBwXg+
sFileName = value; ;P3sDN
} jCa%(2~iQ7
rXPq'k'h#-
d!mtSOh
public int getNSplitter() ms@*JCL!t
{ ^V#9{)B
return nSplitter; "7mYs)=
} UE3(L ^
# -e
WvQK$}Ax4N
public void setNSplitter(int nCount) *$~H=4t
{ N}HQvlLkF9
nSplitter = nCount; BQu_)@
} kclClB:PS
} W ZdEfY{
#; CC"
>>oR@
/* #9M6 q
**Utility.java ^x-vOGlR
*/ MB06=N
package NetFox; ?f<JwF<
nk|j(D
/n;Ll](ri
public class Utility { (L}
rH Et]Xa
FKRO0%M4}Z
public Utility() #}*w &y
{ ,#:*dl
6;6a.iZ
qkVGa%^
} \n$s5i-
G- wQ weJ9
//线程睡眠 +aR.t@D+"Y
public static void sleep(int nSecond) HI)MBrj;r
{ 4+2XPaIm
try{ {\3k(NdEX
Thread.sleep(nSecond); (7/fsfsF
} `B'*ln'r5
catch(Exception e) $8zsqd 4?
{ K=T]@ix$
e.printStackTrace (); ^K*uP^B=
} BB@I|)9O(
} WJ":BK{NM
golr,+LSo
//日志 Ww-%s9N<
public static void log(String sMsg) #2l6'gWE0
{ Fb#.Gg9b>
System.err.println(sMsg); _yk} [x0>
} M0VC-\W7f
xEdCGwgp#
hp=TWt~
public static void log(int sMsg) =.NZ{G
{ Au3>=x`
System.err.println(sMsg); x}o]R
} l}odW
} t9T3e
k.=67L
a Mp*Ap
/* B^g+_;
**TestMethod.java banie{ e
*/ G%0G$3W"
package NetFox; H^_]' ~.
rw_T&>!
dayp1%d
public class TestMethod { JA0$Fz
m| 8%%E}d
$Gt1T[:QUX
public TestMethod() N5 ITb0Tv
{ ///xx/weblogic60b2_win.exe }%LwaRT
try{ `~|8eKFq!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pgT XyAP{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U7O]g'BP
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6&V4W"k
fileFetch.start(); \;AW/&Ea
} B198_T!
catch(Exception e){e.printStackTrace ();} +bK[3KG4F5
f5D.wSY
[)UF@Sq4+Q
} 18JhC*in
0_b7*\xc
;4.D%
public static void main(String[] args) <K4`GT"n
{ 09?n5x!6
new TestMethod(); Yas!w'
} Q|eRek
} $tvGS6p>
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