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)); p l^;'|=M
} :WRD<D_4
for(int i=0;i<nEndPos.length-1;i++) uzxwJs'fz
{ = 9Yfo,F
nEndPos = nStartPos[i+1]; y CHOg
} VKPEoy8H
nEndPos[nEndPos.length-1] = nFileLength; wa,`BAKJ+F
} *w;?&)8%
} S }`f&
79 4UY
K1X-<5]{
//启动子线程 Y-})/zFc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D zD5n
for(int i=0;i<nStartPos.length;i++) ~0,v Q
{ j)/Vtf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jvQ^Vh!mC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {*;8`+R&
nStartPos,nEndPos,i); !%$[p'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bYLYJ`hH<R
fileSplitterFetch.start(); x"Ll/E)\v]
} N?m)u,6-l
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9X*Z\-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); IiniaVuQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <%.%q
nEndPos = " + nFileLength); te[uAJ1 N
// fileSplitterFetch[nPos.length-1].start(); O^\:J2I(
cS Lj\'`b
q5r7KYH{
//等待子线程结束 2W0nA t
//int count = 0; hbYstK;]Z
//是否结束while循环 /$%&fo\[
boolean breakWhile = false; `.;U)}Tn
KK 7}q<&i
7[=G;2<
while(!bStop) 8qkQ*uJP
{ dm/3{\ 4
write_nPos(); 7W}%ralkg
Utility.sleep(500); "yH?df24
breakWhile = true; !r.-7hR$
274j7Y'
9+y&&;p
for(int i=0;i<nStartPos.length;i++) ~ ?nn(Q-
{ dlvU=^G#G
if(!fileSplitterFetch.bDownOver) r3x;lICx-
{ ]+`K\G ^X
breakWhile = false; ds`YVXKH
break; FrMXf,}
} \\EX'L
} 9Avj\G
if(breakWhile) &wU"6E
break; ,62~u'hR5
e,#w*|
;S^"Y:7)
//count++; \ o2oQ3
//if(count>4) [<i3l'V/[
// siteStop(); 5 `TMqrk
} M>=@Z*u/+
~I N g9|
:kcqf,7
System.err.println("文件下载结束！"); &(<>} r
} <`-sS]=d}
catch(Exception e){e.printStackTrace ();} l'<&H#A;'
} PO5,lcBD<
\roJf&O }
pGU.+[|(
//获得文件长度 W0x9^'=s\
public long getFileSize() v8)wu=u
{ \ P6 !
int nFileLength = -1; 7>im2"zm
try{ ,l!>+@
URL url = new URL(siteInfoBean.getSSiteURL()); An>ai N]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9Znc|<
httpConnection.setRequestProperty("User-Agent","NetFox"); b`%u}^B {
<- sr&
\6GNKeN
int responseCode=httpConnection.getResponseCode(); V%[t'uh
if(responseCode>=400) {_W8Qm`.
{ U}HSL5v
processErrorCode(responseCode); /Q9Cvj)"
return -2; //-2 represent access is error q8ZxeMqx%
} _=x*yDPG}
851BOkRal4
q/w5Dx|:
String sHeader; tHaHBx1P
bkR~>F]FAu
0-OKbw5%=b
for(int i=1;;i++) QpzdlB44l
{ <gX({FA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <9H3d7%
//Utility.log(in.readLine()); Q7pCF,;
sHeader=httpConnection.getHeaderFieldKey(i); vD2(M1Q
if(sHeader!=null) :?EZ\WM7
{ Lm!]m\LRZD
if(sHeader.equals("Content-Length")) C!547(l[
{ 29 !QE>Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &!;o[joG
break; c{`!$Z'k<
} ((AK7hb
} PC"=B[OlJ
else 4D5Wse
break; D$KP>G
} | J'k9W"
} q%bFR[p<*
catch(IOException e){e.printStackTrace ();} (Of`VT3ZOA
catch(Exception e){e.printStackTrace ();} *eD[[HbKX
l %zbx"%x
s`Z.H5V>\
Utility.log(nFileLength); G$_)X%Vb I
{8":cn j
QgH{J80
return nFileLength; ekfa"X_
} 5KbPpKpd
i\Yd_
Q7`)&^ Hx
//保存下载信息（文件指针位置） @)MG&X
private void write_nPos() jB9~'>JY
{ S_*Gv O
try{ rpEIDhHv
output = new DataOutputStream(new FileOutputStream(tmpFile)); F@z%y'5 Z*
output.writeInt(nStartPos.length); [ZG>FJDl8
for(int i=0;i<nStartPos.length;i++) |0p@'X1
{ RwK6u-u#9
// output.writeLong(nPos); b&,ZmDJh
output.writeLong(fileSplitterFetch.nStartPos); .|DrXJ\c
output.writeLong(fileSplitterFetch.nEndPos); 5m@'( ]j
} qoT&N,/
output.close(); TqS s*as5
} 5s%e9x|kP
catch(IOException e){e.printStackTrace ();} cJ?,\@uuP
catch(Exception e){e.printStackTrace ();} FW2x
} 1foG*
:SwA) (1
|ggtb\W
//读取保存的下载信息（文件指针位置） /J"fbBXwY
private void read_nPos() !:xE X~
{ 7uUq+dp
try{ AW_YlS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i,;a( Sy4
int nCount = input.readInt(); SG~HzQ\%
nStartPos = new long[nCount]; TXd6o=
nEndPos = new long[nCount]; D'moy*E
for(int i=0;i<nStartPos.length;i++) rkh%[o9"/
{ .`u8(S+
nStartPos = input.readLong(); F&CvqPI
nEndPos = input.readLong(); ZJFF4($qN
} >^W6'Q$P<
input.close(); F;/^5T3wI
} fGH)Fgo`
catch(IOException e){e.printStackTrace ();} #u"@q< )
catch(Exception e){e.printStackTrace ();} s7jNRY V
} fhdqes])
rT-.'aQ2t
%#EzZD
private void processErrorCode(int nErrorCode) LH`$<p2''r
{ a_\7Ho$^
System.err.println("Error Code : " + nErrorCode); 2!9W:I7
} s LDEa
$zhvI*0
ut]&3f''
//停止文件下载 iBWEZw)
public void siteStop() ME)='~E
{ $t6t 6<M)
bStop = true; SY.koW
for(int i=0;i<nStartPos.length;i++) g@t..xJ,
fileSplitterFetch.splitterStop(); B4zuWCE@
5KTFf6Uq
?|`n&HrP
} PxWH)4
} gDw(_KC
//负责部分文件的抓取 &_@M 6[-
**FileSplitterFetch.java 7^@ 1cA=S
*/ 2=<,#7zlJ
package NetFox; ())_4 <
!Dc;R+Ir0!
I"8Z'<|/\q
import java.io.*; qv2J0'd'.
import java.net.*; VWYNq^<AT
e<8KZ
iB~dO @
public class FileSplitterFetch extends Thread { S<*1b 6%D
+?QHSIQo
sVnq|[ /
String sURL; //File URL W<O/LHKHdn
long nStartPos; //File Snippet Start Position <Vh5`-J
long nEndPos; //File Snippet End Position pvWj)4e
int nThreadID; //Thread's ID t"~X6o|R
boolean bDownOver = false; //Downing is over 1 K^-tms
boolean bStop = false; //Stop identical {65YTt%
FileAccessI fileAccessI = null; //File Access interface 5,O:"3>c
ZOppec1D
eH*i_g'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gC%$)4-:
{ cdI"=B+C\
this.sURL = sURL; c>r~pY~$
this.nStartPos = nStart; b;vVlIG
this.nEndPos = nEnd; 2>J;P C[;
nThreadID = id; JHg;2xm"<K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1xsJz^%V
} i$:yq.DW
P;X0L{u0H
6%o@!|=I
public void run() tp ky
{ E=bZ4 /
while(nStartPos < nEndPos && !bStop) ={p<|8`"
{ xvWP^Qkb
,WoB)V.{(
*uxKI:rB:
try{ }`2+`w%uZ
URL url = new URL(sURL); az}zoFl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R(}!gv}s
httpConnection.setRequestProperty("User-Agent","NetFox"); ;d}n89DXj
String sProperty = "bytes="+nStartPos+"-"; %X\Rfn0J"
httpConnection.setRequestProperty("RANGE",sProperty); w8KxEV=
Utility.log(sProperty); ;?-{Uk
`$JOFLa
D-m%eP.
InputStream input = httpConnection.getInputStream(); ePSD#kY5
//logResponseHead(httpConnection); |\C.il7
,W]}mqV%.'
:4\_upRE
byte[] b = new byte[1024]; h7xgLe@
int nRead; h-m0Ro?6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,oEAWNbgQ
{ b$*G&d5
nStartPos += fileAccessI.write(b,0,nRead); Jcp=<z*0
//if(nThreadID == 1) d(5j#?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p-z!i+
} (f*r
AO7X-,
7 lq$PsC
Utility.log("Thread " + nThreadID + " is over!"); L<Z2
bDownOver = true; ?Qpi(Czbpq
//nPos = fileAccessI.write (b,0,nRead); S!iDPl~
} # ?u bvSdU
catch(Exception e){e.printStackTrace ();} ?]}=4
} D{+D.4\
} 1P BnGQYM
F=UW[zy/[
pC&i!la{o}
//打印回应的头信息 09iD| $~
public void logResponseHead(HttpURLConnection con) [eDRghK
{ g)<[-Q1
for(int i=1;;i++) /pGx!
{ 1aUu:#c
String header=con.getHeaderFieldKey(i); K$$%j"s
if(header!=null) S;{[];
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m .En!~t
Utility.log(header+" : "+con.getHeaderField(header)); C+C1(b;1
else 0.wN&:I8t
break; :yOJL [x
} pQm-Hr78j
} v1NFz>Hx
BK.RYSN
(<|1/^~=
public void splitterStop() q}&+{dN\1
{ You~ 6d6Om
bStop = true; L[:M[,?=`
} .4=A:9
d%1Vby
NVDvd6
} oTpoh]|[
J=#9eW
^$8WV&5q>
/* tkHUX!Ow;
**FileAccess.java 52*KRq o
*//文件访问(定位，写) r"lh\C|
package NetFox; &{x`K4N
import java.io.*; _<)HFg6
7{[i)
tkdyR1-
public class FileAccessI implements Serializable{ uF T5Z
EmV ZqW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9lX+?m~ ~
RandomAccessFile oSavedFile; (=s%>lW|
long nPos; %S%0/
u z:@
)Mw 3ZE92
public FileAccessI() throws IOException 7$:Jea
{ MV?sr[V-oP
this("",0); +AOpB L'
} t`x_@pr
y)`q% J&
PO0/C q)
public FileAccessI(String sName,long nPos) throws IOException d 4;
{ 42 rIIJ1A
oSavedFile = new RandomAccessFile(sName,"rw"); S^@#%>
this.nPos = nPos; `6G:<wX
oSavedFile.seek(nPos); u$1^=
} 5S #6{Y =
\Xg`@JrTM
;;zd/n2b
public synchronized int write(byte[] b,int nStart,int nLen) '/F~vSQsR
{ o@|kq1m8
int n = -1; [i]%PVGW
try{ ]Ai!G7s8P
oSavedFile.write(b,nStart,nLen); )B Xl|V,
n = nLen; 5R#:ALwX:
} Now2ad&
catch(IOException e) I]N!cEr;@-
{ '\LU 8VC
e.printStackTrace (); C2K<CDVw
} 3;EBKGg|
?)"v~vs
n,|YJ,v[
return n; /_/Z/D!
} z-h7v5i"
yc@:*Z
bKPjxN?!9
} #r80FVwiD
G4,BcCPQ
.J9\Fr@
/* 8"x\kSMb
**SiteInfoBean.java h,2?+}Fn
*/ 9h^TOZK)
package NetFox; g);.".@"
$s5D/60nO
<D(|}5qR
public class SiteInfoBean { ~fly6j|u
ltmD=-]G_
q62U+o9G
private String sSiteURL; //Site's URL d>1#|
private String sFilePath; //Saved File's Path 7e<\11uI]a
private String sFileName; //Saved File's Name v7D3aWoe
private int nSplitter; //Count of Splited Downloading File KKJa?e`C
qnU$Pd
vXcgl
public SiteInfoBean() 4ak} "Z
{//nSplitter的缺省值为5 3_c4+u"6
//default value of nSplitter is 5 [[8h*[:
this("","","",5); HlX2:\\
} ]"\XTL0
VDPq3`$+v{
Wi!$bL`l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (:J U
{ G)y'exk
sSiteURL= sURL; 4 !M6RL8{
sFilePath = sPath; F}_Zh9/$(
sFileName = sName; ${, !Ll7)
this.nSplitter = nSpiltter; m:5bb3
L"V~MF
wHhIa3_v
} DBzF\-
ZZF\;
azpXE
public String getSSiteURL() Hbz,3{o5
{ BjbpRQ,
return sSiteURL; '3ZYoA%
} >U')ICD~
H6-{(: *<
#h7$b@
public void setSSiteURL(String value) 'd|E>8fejG
{ <=!|U0YV
sSiteURL = value; #Xd#Ncj
} ou'|e"tI
4 {3< `
-*&C "%e
public String getSFilePath() N!=Q]\ZD
{ 5[>N[}Ck>
return sFilePath; dZjh@yGP.
} ,zrShliU
%Z6\W; (n
Zl`sY5{1
public void setSFilePath(String value) N`i`[ f
{ %c,CfhEV%&
sFilePath = value; 55|.MXzq
} 7!E7XP6,~>
E 5bo60z
Z~Z+Yt;,9a
public String getSFileName() `_H^k!^
{ v_ W03\
return sFileName; t%>x}b"2T
} AZjj71UE
I~I$/j]e`
]%/a'[
public void setSFileName(String value) ]$96#}7N
{ nXF|AeAco
sFileName = value; z6Jfu:_N!
} b'~IFNt*^
i3\6*$Ug
9k>=y n
public int getNSplitter() |{@_J
{ @IwVR
return nSplitter; QG=&{-I~[3
} SB`"%6
U?Icyn3q0
HFd>UdT%
public void setNSplitter(int nCount) vxC,8Z
{ auT$-Ki8
nSplitter = nCount; i#y3QCNqf^
} 6J%+pt[tu
} j{a3AEmps
iVGc\6+'
*Ad7GG1/u
/* yS:1F PA$_
**Utility.java 2Md'<.
*/ IKV:J9
package NetFox; ZIrJ"*QO=
A?sU[b6_
We*)RXm%
public class Utility { n/]$k4h
Yl6\}_h`
~_Mz05J-\_
public Utility() :-kXZe
{ ]w=6.LzO*
juuV3et
iy_\1jB0
} zx{O/v KG
r'ydjy
//线程睡眠 5=.EngG
public static void sleep(int nSecond) q#~]Hp=W5
{ 35[8XD
try{ XK5qE"
Thread.sleep(nSecond); = A !;`G
} /RmHG H!
catch(Exception e) _}B:SM
{ R?Or=W)i
e.printStackTrace (); ~:%rg H
} K9y!ZoB
} nC5
NK@G0p~O
//日志 &`'gO 9
public static void log(String sMsg) 7E9h!<5v
{ .1F^=C.w
System.err.println(sMsg); H19CVc\B
} k98}Jx7J)"
L){rv)?="
_8'FI_E3
public static void log(int sMsg) k&1~yW
{ '.wyfSH@
System.err.println(sMsg); y[l19eU
} RZ[r XV5
} )ccdfSe
1Bz'$u;
FT* o;&_QS
/* jbqhNsTNK
**TestMethod.java ^Q?I8,4}
*/ GBZx@B[TY
package NetFox; =R^V[zTn_
?_F,HhQ
0F<O \
public class TestMethod { w^&TG3m1~
^E7>!Lbvx
?)cNe:KY
public TestMethod() $[Fh|%\
{ ///xx/weblogic60b2_win.exe ntSPHK|'
try{ F=hfbCF5x
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uj-q@IKe
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -hP@L ++D
SiteFileFetch fileFetch = new SiteFileFetch(bean); khb Gyg%
fileFetch.start(); %L./U$
} ?~aM<rcZ
catch(Exception e){e.printStackTrace ();} jz$)*Kdi*
-< 7KW0CA
OZ q/'*
} WbS2w @8
8<t?o'9I
<&o `T4
public static void main(String[] args) .O'gD.|^N
{ <)]B$~(a
new TestMethod(); m//(1hWv7
} `oh'rm3'8
} 1Ly?XNS
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