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)); [2GXAvXsT
} M1AZ}bc0]
for(int i=0;i<nEndPos.length-1;i++) zW"~YaO%C
{ @9OeC O
nEndPos = nStartPos[i+1]; G 2%
} o &BPG@n
nEndPos[nEndPos.length-1] = nFileLength; OW+e_im}
} QD$}-D[
} [c&2i`C
hlAR[]
{l0,T0
//启动子线程 /]ku$.mr\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {PN:bb
for(int i=0;i<nStartPos.length;i++) `4VO&lRm
{ &mh Ln4^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d^KBIz8$5l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^G}# jg.
nStartPos,nEndPos,i); >Hdjsu5{N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vP3K7En
fileSplitterFetch.start(); uz*d^gr}
} E4Y"X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -'80>[}q/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xK$}QZ)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /a@ kS
nEndPos = " + nFileLength); Y3-]+y%l
// fileSplitterFetch[nPos.length-1].start(); q{a#HnZo"
e{,!|LhpQ
yJnPD/i
//等待子线程结束 ]UK`?J=t2g
//int count = 0; :&Qb>PH[
//是否结束while循环 'n~fR]h}
boolean breakWhile = false; sS C?io
OI~}e,[2z
]}BB/KQy^
while(!bStop) CfQf7-
{ y7CWBTH0>
write_nPos(); 5B}3GBA
Utility.sleep(500); (FM4 ^#6
breakWhile = true; @q,)fBZq
Q2*/`L}m\
N1PECLS?
for(int i=0;i<nStartPos.length;i++) O x{Q.l
{ {J{1`@
if(!fileSplitterFetch.bDownOver) ;!'qtw"CB
{ m'd^?Qc
breakWhile = false; ;xL67e%?
break; h]qT1(I
} F vj{@B!
} +Qt[1Xq
if(breakWhile) ]x1p!TSU
break; ,,S9$@R
K6E}";;
!]yQ1@)*'
//count++; G]b8]3^
//if(count>4) mj)PLZ]
// siteStop(); L*P_vCC
} [d}qG#N
,aI,2U91
d;{y`4p)s
System.err.println("文件下载结束！"); qc3~cH.@
} ])C>\@c6Gm
catch(Exception e){e.printStackTrace ();} }xqXd%uz
} $)Wb#B
@\ }sb]
TfL4_IAG.
//获得文件长度 X&s7%]n+
public long getFileSize() :ztyxJv1
{ w5,6$#
int nFileLength = -1; RYt6=R+f
try{ J=):+F=
URL url = new URL(siteInfoBean.getSSiteURL()); 5lO^;.cS,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %8 qSv%_
httpConnection.setRequestProperty("User-Agent","NetFox"); t')h{2&&!2
`Z:3`7c
f7Zf}1|
int responseCode=httpConnection.getResponseCode(); "MTWjW*6
if(responseCode>=400) z4g+2f7h-X
{ eO'xkm
processErrorCode(responseCode); )`<6taKx@n
return -2; //-2 represent access is error @YCv
} zHV|-R
~^x-ym5
)U'yUUi
String sHeader; IdF$Ml#[h
4Hk6b09
r ^MiRa
for(int i=1;;i++) mk\i}U>`
{ y<|)'(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h`lmC]X_
//Utility.log(in.readLine()); lcCJ?!lsSW
sHeader=httpConnection.getHeaderFieldKey(i); dQai4e>[
if(sHeader!=null) [yC"el6PM
{ /tP7uVL R
if(sHeader.equals("Content-Length")) Ae6("Oid
{ ?ZaD=nh$mK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _-/x;C
break; r sLc&2F
} Q&gPa]z]}
} @HvScg*Y
else QNb>rLj52
break; dhW<p5
} !_dR'
} (`pNXQ0n
catch(IOException e){e.printStackTrace ();} %@P``
catch(Exception e){e.printStackTrace ();} [^M|lf
_jmkl B
"7d.i(vw
Utility.log(nFileLength); a1|c2kT
0V3gKd7
EI\v
return nFileLength; XCm\z9F
} =-qf;5[|
q`[K3p
[fxuUmU
//保存下载信息（文件指针位置） q3)wr%!k5D
private void write_nPos() k}zd' /b
{ \B&6TeR
try{ lbS?/f
output = new DataOutputStream(new FileOutputStream(tmpFile)); e/>:K' {
output.writeInt(nStartPos.length); qOi5WX6F/
for(int i=0;i<nStartPos.length;i++) GmbIFOT~
{ # kEOKmO
// output.writeLong(nPos); [sj VRW-
output.writeLong(fileSplitterFetch.nStartPos); G'9{a'
output.writeLong(fileSplitterFetch.nEndPos); /l6\^Xf{
} H|`R4hAk
output.close(); Yx),6C3
} ?q!FG(
catch(IOException e){e.printStackTrace ();} _88QgThb
catch(Exception e){e.printStackTrace ();} Y\p$SN
} 8R}K?+]
@!<d0_dnC
bDWeU}
//读取保存的下载信息（文件指针位置） f05=Mc&)
private void read_nPos() /$:U$JVb?l
{ z]$>+MH_
try{ 13a(FG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [4XC#OgA
int nCount = input.readInt(); @KA1"Wb_
nStartPos = new long[nCount]; ;v_V+t<$
nEndPos = new long[nCount]; O:^'x*}
for(int i=0;i<nStartPos.length;i++) l E^*t`+
{ c#QFG1
nStartPos = input.readLong(); qo_]ZKL44
nEndPos = input.readLong(); JKy#j g:#
} ue6d~8&
input.close(); $KX[Zu%
} EZib1g&:R/
catch(IOException e){e.printStackTrace ();} 7~b!4x|Z
catch(Exception e){e.printStackTrace ();} kaQ2A
} 9tk" :ld
9!}q{2j
G52Z)^
private void processErrorCode(int nErrorCode) `(DJs-xD
{ MCU9O
System.err.println("Error Code : " + nErrorCode); s4$X
} /.$L"u
^PqMi:htc
iCrxV{
//停止文件下载 #6W,6(#^#
public void siteStop() nU/;2=f<
{ SY1GR n
bStop = true; 0^#DNq*NQ
for(int i=0;i<nStartPos.length;i++) p7C!G1+z
fileSplitterFetch.splitterStop(); >vujZw_0>
jK3\K/ob(
,[`$JNc
} *vnXlV4L
} xmr|'}Pt[
//负责部分文件的抓取 p)3nyN=|_
**FileSplitterFetch.java :c7CiP
*/ ?2ItB`<(
package NetFox; ArzDI{1
@B`Md3$7
QU/3X 1W
import java.io.*; tg85:
import java.net.*; eN/G i<
OVR?*"N_
1h=D4yN
public class FileSplitterFetch extends Thread { z(H?VfJo
q4ipumy*
=yqHC<8:
String sURL; //File URL jPk c3dG +
long nStartPos; //File Snippet Start Position vZkXt!%)
long nEndPos; //File Snippet End Position |nY~ZVTt/
int nThreadID; //Thread's ID [w+Q^\%bN
boolean bDownOver = false; //Downing is over hNbIpi=
boolean bStop = false; //Stop identical >]&X ^V%Q#
FileAccessI fileAccessI = null; //File Access interface V=}1[^
~R.dPUr
eko]H!Ov(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `#6x=24
{ |RhM| i
this.sURL = sURL; B:9.e?t
this.nStartPos = nStart; Sj-[%D*
this.nEndPos = nEnd; IU!Ht>
nThreadID = id; q*8lnk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J%Mnjk^_\S
} B~TN/sd
@6&JR<g*t
;h~er6&
public void run() \%5MAQS
{ r]LCvsVa
while(nStartPos < nEndPos && !bStop) AhxGj+
{ C1QV[bJK
#w>~u2W
7[KCWJ
try{ "!Lkp2\
URL url = new URL(sURL); :a3xvN-l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [B9;?G
httpConnection.setRequestProperty("User-Agent","NetFox"); Gt~JA0+C)7
String sProperty = "bytes="+nStartPos+"-"; nQ=aLV+'
httpConnection.setRequestProperty("RANGE",sProperty); qLjT.7 .x
Utility.log(sProperty); YG[w@u
uLVBM]Qj
'4u v3)P
InputStream input = httpConnection.getInputStream(); !wh&>3~
//logResponseHead(httpConnection); 'fY9a(Xt.
HI!4
({[,$dEa;
byte[] b = new byte[1024]; #I%s3
int nRead; -MfQ&U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FtIa*j^G
{ p2d\ZgWD=)
nStartPos += fileAccessI.write(b,0,nRead); '*R%^RK
//if(nThreadID == 1) 4%_M27bu[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R^8{bP
} X9XI;c;b-
[,g~m9
sN/+
Utility.log("Thread " + nThreadID + " is over!"); l[%lE
bDownOver = true; (E!!pz
//nPos = fileAccessI.write (b,0,nRead); Z'M`}3O
} YYUe)j{T
catch(Exception e){e.printStackTrace ();} #Ufo)\x
} 213\ehhG<
} >Ko[Xb-8^_
`\b+[Nes
*jCW.ZLY
//打印回应的头信息 J(iV0LAZb
public void logResponseHead(HttpURLConnection con) "2hh-L7ql
{ |4C^$
for(int i=1;;i++) LE;g 0s
{ 6 hiC?2b{x
String header=con.getHeaderFieldKey(i); h$fe -G#
if(header!=null) vVVPw?Ww-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j[e,?!8;
Utility.log(header+" : "+con.getHeaderField(header)); ;BBpN`T
else lG"H4Aa>
break; yV]xRaRr2
} R$6qoqv{yG
} }5bM1h#z
+nU.p/cK+\
3-x%wD.
public void splitterStop() w*~Tm>U
{ OJ,m1{9$}
bStop = true; h?j_Ry
} `X -<$x
I3)Zr+
5w<A;f
} Yc#IFmC}
UI?=]"
J@#?@0]F
/* c`kQvXx
**FileAccess.java 2`Gv5}LfyR
*//文件访问(定位，写) REA;x-u*
package NetFox; KoHGweKl#
import java.io.*; rt!r2dq"
Ai kf|)D[
$>w/Cy
public class FileAccessI implements Serializable{ !j^&gRH
bFGDgwe z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {o|k.zy
RandomAccessFile oSavedFile; f/ahwz
long nPos; "J19*<~
, =y#m-9
ClQe4uo{
public FileAccessI() throws IOException x';uCKWV
{ CL9yEy"V
this("",0); r"]'`qP,
} W{Z^n(f4
;l!`C':'
yrr) y
public FileAccessI(String sName,long nPos) throws IOException ?R'Y?b
{ \}dyS8
oSavedFile = new RandomAccessFile(sName,"rw"); ZYMw}]#((E
this.nPos = nPos; s3 B'>RG}
oSavedFile.seek(nPos); 6STp>@Ch]"
} (Hp'B))2
p>kq+mP2bc
FFcB54ALTf
public synchronized int write(byte[] b,int nStart,int nLen) hIU(P Dl4
{ R7_VXvm>z
int n = -1; D>#l-{d
try{ npH?4S-8G
oSavedFile.write(b,nStart,nLen); aC^$*qN-)
n = nLen; ~5OL6Bi-q
} ai-n z-;
catch(IOException e) HW6.O|3
{ ..qd,9H
e.printStackTrace (); r>n" 51*
} a.kbov(
&ab|2*3?X
K+d2m9C=
return n; jRj=Awy
} X6@wkrf-
JUt7En;XE
M+Uyb7
} %1}6q`:w
K-Mc6
aMwB>bt
/* i[nF.I5*f
**SiteInfoBean.java X0$@Ik
*/ MXZ>"G
package NetFox; uA~slS Z
B3 zk(RNZ
:1aL ?
public class SiteInfoBean { cxP&^,~
y8 E}2/
|g&ymFc
private String sSiteURL; //Site's URL [EZYsOr.
private String sFilePath; //Saved File's Path s"~5']8
private String sFileName; //Saved File's Name PLR0#).n
private int nSplitter; //Count of Splited Downloading File s] au/T6b
4IsG=7
Pqp *
public SiteInfoBean() w"zE_9I\
{//nSplitter的缺省值为5 Q!'qC*Gyfn
//default value of nSplitter is 5 Ew,T5GG
this("","","",5); d8x%SQ!V
} `8g7q 5
WFv!Pbq,
,.mBJSE3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }iiHr|l3
{ 0kDBE3i#
sSiteURL= sURL; R: Z_g!h
sFilePath = sPath; `jsEN ;<
sFileName = sName; ERz;H!pU8
this.nSplitter = nSpiltter; H[WQ=){
lj[,|[X7`
M\oVA=d\0
} ?dq#e9
dt,3"J
&t}?2>:
public String getSSiteURL() \~DM
{ p]gT&[iJ
return sSiteURL; `!4,jd
} F4C!CUI
+l0g`:
93Yn`Av;
public void setSSiteURL(String value) M"Y0jQ(
{ $P {K2"Oc
sSiteURL = value; ]\c,BWC@e
} + ,4" u
e@]-D FG
~)X[(T{
public String getSFilePath() %w}gzxN^
{ m,MSMw1p
return sFilePath; dQ:cYNm
} I9 64
fg*@<'
LJTo\^*
public void setSFilePath(String value) 2YBIWR8z
{ X_TiqV
sFilePath = value; Lxe^v/LsT
} ;sOsT?)7$
w4};q%OBj
\=e8%.#@J
public String getSFileName() /bVZ::A&_
{ YZwaD b
return sFileName; x4kWLy7Sz
} /@oLe[Mz$
/DFV$+9
}VCI=?-
public void setSFileName(String value) ?UZ?NY
{ Ao.\
sFileName = value; 963aW*r
} DVp5hR_$
`C72sA{M.
(/{aJV
public int getNSplitter() z~oDWANP
{ 4gBp8*2
return nSplitter; >)nS2bOE
} t;q7t!sC]
nvq3*
X`r*ob
public void setNSplitter(int nCount) :}}%#/nd
{ iz^qR={bW
nSplitter = nCount; IyUdZ,ba
} Zj9c9
} C*kK)6v`
Kuw^qX"
C"V%# K
/* [3>GGX[Ic
**Utility.java [0;buVU.
*/ /R8p]
package NetFox; yt0,^*t_
V2d,ksKwn
m@G i6
public class Utility { <^R{U&Z@
%:9oDK
DC4C$AyW r
public Utility() ^4Uw8-/9
{ |`O5Xs1{B
_F(P*[[&
\_]En43mg
} H=c`&N7E
;O#g"8
//线程睡眠 NTs7KSgZ
public static void sleep(int nSecond) vp)Vb^K>
{ /YKMKtE
try{ OYL]j{
Thread.sleep(nSecond); Z=z%$l
} J>0b1
catch(Exception e) 9q[;u[A8^
{ W[''Cc.
e.printStackTrace (); !7p}C-RZp
} vsyWm.E
} |F$BvCg
,_v|#g@{
//日志 n.6T OF
public static void log(String sMsg) `FF8ie8L
{ D)b}f`
System.err.println(sMsg); s'HD{W`
} db72W x0>
;@mRo`D`
Sr Ca3PA
public static void log(int sMsg) _'0 @%P%
{ X"asfA[6K
System.err.println(sMsg); },-*
} Tenf:Hm/k
} wEft4o
'o4p#`R:8
{<$bAj
/* f'En#-?O
**TestMethod.java aEVsU|
*/ <O~WB
package NetFox; \FmKJ\
*s4\\Wb=
a>mMvc"
public class TestMethod { @\P4/+"9
y*b3&%.ml
;iYff N
public TestMethod() u0s8yPA
{ ///xx/weblogic60b2_win.exe T/r#H__`
try{ p]G3)s@>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AC%JC+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); MHj,<|8Q
SiteFileFetch fileFetch = new SiteFileFetch(bean); |pZUlQbb
fileFetch.start(); m"2d$vro"
} (K..k-o`.
catch(Exception e){e.printStackTrace ();} E)N<lh
8AFczeg[[
3)Ac"nuyqH
} O~Wt600{E
)U t5+-UK
T Eu'*>g
public static void main(String[] args) MmTC=/j
{ D1s4`V -
new TestMethod(); .3qu9eP
} .Nm su+s
} T? ,P*l
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