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)); @^W`Yg)C
} O<gfZ>
for(int i=0;i<nEndPos.length-1;i++) #&&T1;z"#
{ u*l|MIi6J
nEndPos = nStartPos[i+1]; Z'JS@dV
} S\e&xUA;|
nEndPos[nEndPos.length-1] = nFileLength; 9)q3cjP{<
} fd\RS1[
} yw3"jdcl
x *eU~e_jP
\c=I!<9
//启动子线程 HGDrH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |cPHl+$nh.
for(int i=0;i<nStartPos.length;i++) k9^Hmhjw
{ D6sw"V#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hRcb}>pr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \oQ]=dDCd%
nStartPos,nEndPos,i); ie}OZM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xvr5$x|h
fileSplitterFetch.start(); K"}fD;3
} mo0\t#jA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p5Q]/DhG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .J"N}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XH:*J+$O
nEndPos = " + nFileLength); !d*[QD8
// fileSplitterFetch[nPos.length-1].start(); "n-'?W!
US6_5>/
<#63tN9
//等待子线程结束 AKNx~!%2
//int count = 0; j=_rUc'Me
//是否结束while循环 mCtS_"W
boolean breakWhile = false; ::L2zVq5V
VSj!Gm0LB
));#oQol9
while(!bStop) PJnC
{ Gn]36~)*H
write_nPos(); ,w }Po
Utility.sleep(500); $6QIYF""
breakWhile = true; H#-3
eE;tiX/
xS18t="
for(int i=0;i<nStartPos.length;i++) e5=d Ev
{ @u3`lhUcT
if(!fileSplitterFetch.bDownOver) MfTLa)Rz
{ N!A20Bv
breakWhile = false; jXcJ/g(X3
break; ejRK-!
} lG*Rw-?a
} k#*-<1
if(breakWhile) &{iC:zp
break; Vs>Pv$kW
b^Hrzn
93-Y(Xx)bY
//count++; TFVQfj$r
//if(count>4) ffCDO\i({
// siteStop(); 2`yhxO
} fF:57*ys
~/:vr
gmTBT#{6yH
System.err.println("文件下载结束！"); .@dC]$2=
} ;'!x
catch(Exception e){e.printStackTrace ();} D+8d^-:
} l,wlxh$}(
NgNGq\!
" T(hcI
//获得文件长度 L aTcBcI
public long getFileSize() V>$( N/1
{ <Ij!x`MS+
int nFileLength = -1; -K"'F`;W
try{ vwR_2u
URL url = new URL(siteInfoBean.getSSiteURL()); CjdM*#9lW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FU|brSt
httpConnection.setRequestProperty("User-Agent","NetFox"); ]A4=/6`g?b
|5@Ra@0
&\zYbGU
int responseCode=httpConnection.getResponseCode(); W?7l-k=S
if(responseCode>=400) wcHk]mLM
{ #ydold{F
processErrorCode(responseCode); O5dS$[`j\p
return -2; //-2 represent access is error Da^q9,|
} 4^_6~YP7
lR(9;3
LPs%^*8(2
String sHeader; j:9M${~
mq:k|w^6
dQX-s=XJ
for(int i=1;;i++) $m`Dyu
{ .Xg.,kW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OqGp|`
//Utility.log(in.readLine()); I2}W/}
sHeader=httpConnection.getHeaderFieldKey(i); ! FcGa
if(sHeader!=null) UG1<Xfu|
{ iAd&o`C
if(sHeader.equals("Content-Length")) ZvY"yl?e
{ OjU{r N*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V:0IBbh)w
break; ^`H'LD
} M-WSdG[AJ
} B=Hd:P|
else O[X*F2LC4
break; z$^d_)
} HOW<IZ^
} PW*Vfjf4
catch(IOException e){e.printStackTrace ();} --HDEc|
catch(Exception e){e.printStackTrace ();} 8lQ/cGAc
VPCI5mS_
j/v>,MM
Utility.log(nFileLength); 4+olyBht
bGh&@&dHr
ra^</o/
return nFileLength; \Y#
} qxRsq&_
e9acI>^w
g4W$MI
//保存下载信息（文件指针位置） $W._FAAJ#
private void write_nPos() ui]iOp
{ 1q}32^>+o
try{ ,#a4P`q'iC
output = new DataOutputStream(new FileOutputStream(tmpFile)); NF$6yv9C
output.writeInt(nStartPos.length); DpHubqWz
for(int i=0;i<nStartPos.length;i++) vbJ<|#|r-
{ v}>g* @
// output.writeLong(nPos); mF gqM:
output.writeLong(fileSplitterFetch.nStartPos); CKw-HgXG
output.writeLong(fileSplitterFetch.nEndPos); LcKc#)'EE
} ?[Yn<|
output.close(); %6ckau1_;
} DLwlA!z
catch(IOException e){e.printStackTrace ();} `(W"wC
catch(Exception e){e.printStackTrace ();} |dIR v
} :GvC#2p
e.\>GwM
RqROl!6
//读取保存的下载信息（文件指针位置） cGE{dWz
private void read_nPos() 1@Ba7>%'
{ ?M90K)&g{
try{ (JU8F-/9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |\bNFnn(
int nCount = input.readInt(); 8;M,l2pmR{
nStartPos = new long[nCount]; #kQ! GMZH
nEndPos = new long[nCount]; n%r>W^2j
for(int i=0;i<nStartPos.length;i++) ;apLMMsWC
{ zDg*ds\
nStartPos = input.readLong(); 8hV]t'/;
nEndPos = input.readLong(); ( w4XqVT
} l(Y32]Z
input.close(); Ioe.[&o6B
} ~U+<JC Z
catch(IOException e){e.printStackTrace ();} kr$)nf
catch(Exception e){e.printStackTrace ();} hLfWDf*T|
} h5{//0 y
+s}!+I8P
7L+Wj }m
private void processErrorCode(int nErrorCode) 2?(/$F9X,
{ M_O$]^I3w
System.err.println("Error Code : " + nErrorCode); (,"%fc7<i
} J^t0M\
Gb2|e.z
%X\J%Fj
//停止文件下载 X6sZwb
public void siteStop() d%@0xsU1
{ !yg &zzP*
bStop = true; ,%Pn.E* r;
for(int i=0;i<nStartPos.length;i++) Sw$&E
fileSplitterFetch.splitterStop(); )fXxkOd
D~qi6@Ga
qV=O;
} ym p*:lH(
} j %MY6"
//负责部分文件的抓取 7<kr|-
**FileSplitterFetch.java va~:Ivl-)
*/ y2k's
package NetFox; SFzoRI=qG
8<Nz34Y
ldG8hK
import java.io.*; &WCVdZK:
import java.net.*; 7d{xXJ-
@#"K6
wV-N\5!r%H
public class FileSplitterFetch extends Thread { [)IaXa
h1)+QLI
sS)tSt{C
String sURL; //File URL 7F~Jz*,B*W
long nStartPos; //File Snippet Start Position aSm</@tO&
long nEndPos; //File Snippet End Position YC{7;=Pf
int nThreadID; //Thread's ID Z(E.F,k
boolean bDownOver = false; //Downing is over u`L*
boolean bStop = false; //Stop identical z:n JN%Qb
FileAccessI fileAccessI = null; //File Access interface "{{@N4^
HDo=WqG
N}|1oQkjf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $ z+ =lF
{ JjAO9j%
this.sURL = sURL; kSJ:4!lFU
this.nStartPos = nStart; <^Q` y
this.nEndPos = nEnd; LQ$dT#z2A
nThreadID = id; c1]\.s
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?s0")R&
} d{^K8T3
@S012} xH
lZ+1A0e
public void run() Tq6@ 1j6p
{ |qk%UN<
while(nStartPos < nEndPos && !bStop) `Q^Vm3h
{ {.,y v>%
[s!cc:JR
[yAR%]i-7
try{ 9/\=6vC|
URL url = new URL(sURL); !hPe*pPVV)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Bsz;GnD|r
httpConnection.setRequestProperty("User-Agent","NetFox"); qr/N?,
String sProperty = "bytes="+nStartPos+"-"; I'cM\^/h
httpConnection.setRequestProperty("RANGE",sProperty); !P)7t`X
Utility.log(sProperty); _`94CC:
XG6UV('
?@_,_gTQ
InputStream input = httpConnection.getInputStream(); XN'X&J
//logResponseHead(httpConnection); 20uR?/|@
M7lMOG(\
|}roR{gc|
byte[] b = new byte[1024]; X"G3lG
int nRead; yIThzyS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mCpoaGV_
{ t#g6rh&
nStartPos += fileAccessI.write(b,0,nRead); w3IU'(|G
//if(nThreadID == 1) uRNc9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8>jd2'v{
} KK*"s^L
hMs}r,*
fx4X!(w!B
Utility.log("Thread " + nThreadID + " is over!"); .!t'&eV
bDownOver = true; Uz!cVs?-
//nPos = fileAccessI.write (b,0,nRead); `qsn;
} BPKeG0F7
catch(Exception e){e.printStackTrace ();} l>9ZAI\^
} 5G=CvGu
} _zO,VL
o' DXd[y
Z-j%``I?h
//打印回应的头信息 {4{ACp
public void logResponseHead(HttpURLConnection con) s.I=H^T
{ HgX4RSU
for(int i=1;;i++) A]vQ1*pnk
{ *%cI,}%
String header=con.getHeaderFieldKey(i); -OuMC&
if(header!=null) FyQ^@@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DI!l.w5P_
Utility.log(header+" : "+con.getHeaderField(header)); AuU:613]W8
else Z;i^h,j?$1
break; Kc\0-3 Z
} $y>J=
} U07n7`2w
BiHBu8<
15gI-Qb
public void splitterStop() QTK{JZf
{ .x1EdfHed/
bStop = true; s\Cl3
} :h3 Gk;u
{{=7mbc
+Mv0X%(N
} w>rglm&
!H,R$3~
)mZ`j.
/* 'F[QE9]*
**FileAccess.java c:~o e
*//文件访问(定位，写) ipKkz
package NetFox; iygdX2
import java.io.*; D9c8#k9Y.
T cSj`-
r0j:ll d
public class FileAccessI implements Serializable{ TiF$',WMv
+V7*vlx-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ZT_EpT=1
RandomAccessFile oSavedFile; F+Lq
long nPos; ~&4,w9b)j
I[<C)IG
D@4hQC\
public FileAccessI() throws IOException FQ(=Fnqn
{ OjeM#s#N!
this("",0); -F|(Y1OE
} 'n.eCdj
^X0<ZI
iAWPE`u4
public FileAccessI(String sName,long nPos) throws IOException t_@%4Wn!1L
{ D@d/O
oSavedFile = new RandomAccessFile(sName,"rw"); bUz7!M$
this.nPos = nPos; &sWqSS
oSavedFile.seek(nPos); D 7H$!(F>
} Ql\{^s+
cKK 1$x
}e9:2
public synchronized int write(byte[] b,int nStart,int nLen) WRFzb0;01
{ nKkI
int n = -1; o $p*C
try{ 4( ^Ht
oSavedFile.write(b,nStart,nLen); gnB%/g[_
n = nLen; /_woCLwQ#
} zj`!ZY?fv
catch(IOException e) OYNs1yB
{ X )g<F
e.printStackTrace (); CQzJ_aSJ(
} nvsuF)%9hZ
{o5E#<)
:)?w2'O
return n; ],&WA?>G
} d^WVWk K
<q%buyQna
JyYg)f
} SgFyv<6>:
*)U=ZO6S
p^7ZFUP
/* @+:S'mAQC
**SiteInfoBean.java }O5c.3
*/ ~%k<N/B
package NetFox; zpiqJEf|'"
?7/n s>}
lySeq^y?Q
public class SiteInfoBean { q%"]}@a0
I%b, H`
4=>/x90y
private String sSiteURL; //Site's URL G;qC&7T
private String sFilePath; //Saved File's Path Mfuw y
private String sFileName; //Saved File's Name I(bH.{1n7
private int nSplitter; //Count of Splited Downloading File $^y6>@~
H)G ^ Y1
@T|mHfQ8
public SiteInfoBean() G?8LYg!-
{//nSplitter的缺省值为5 kf~ D m}bV
//default value of nSplitter is 5 S;I>W&U
this("","","",5); ]ChGi[B~9
} 8kRqF?rbj
\>G:mMk/
3*v&6/K
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~MpcVI_K
{ !GAU?J;<#2
sSiteURL= sURL; SjmWlf,
sFilePath = sPath; 3}F{a8iIm
sFileName = sName; _rN1(=J
this.nSplitter = nSpiltter; ^*$lCUv8p
&{R]v/{p]
N!Q~?/!d
} QnZ7e#@UP
Z'<I Is:J
32S5Ai@Cd"
public String getSSiteURL() S9;:)
{ &F 3'tf?
return sSiteURL; wBJP8wES=
} b\.l!vn0
d%(4s~y
`,7;2ZG~O
public void setSSiteURL(String value) hgU#2`fS
{ %"gV>E_u
sSiteURL = value; g.:b\JE`
} >39\u&)
c`M ,KXott
v-MrurQ4
public String getSFilePath() BXxl-x
{ <cUaIb;(4
return sFilePath; ~]l T>|X
} LvcGh
`9vCl@"IV
&f"kWOe$X
public void setSFilePath(String value) OGGuVY
{ :&-j{8p-
sFilePath = value; j-n-2:Q
} =K`]$Og}8
Z{p62|+Ck@
5n#@,V.O/
public String getSFileName() IPxK$nI^
{ UPr8Q^wm
return sFileName; e"u89acp
} [+_0y[~,tB
M?3#XQDvD
cpJ(77e
public void setSFileName(String value) Ed ,O>(
{ Uoqt
sFileName = value; r)/nx@x
} /q\{OsrX
m{VC1BkZ
>"%}x{|
public int getNSplitter() j%TcW!D-_
{ >6\rhx>
return nSplitter; lr-:o@q{
} ,K 1X/),
IHaNg K2
u^Ss8}d
public void setNSplitter(int nCount) t^KoqJ
{ r!WXD9#
nSplitter = nCount; oHvVZ
} D8r=Vf
} 7O^'?L<C'
/'WIgP
Im0#_ \
/* Q ,6[
**Utility.java cUPC8k.1
*/ B(l8&
package NetFox; iTpU4Qsj
+i1\],7
0*umf.R
public class Utility { qt&zo5
%@4/W N
!5escR!\D
public Utility() ZA!yw7~
{ * U#@M3g.
),#hBB`ZA
JAA{5@ST
} 2ij/!
[tEHr
//线程睡眠 kV$$GLD\
public static void sleep(int nSecond) &:MfLDJ
{ rh%-va9
try{ )VoQ/ch<
Thread.sleep(nSecond); !/|^ )d^U
} hD I}V1)
catch(Exception e) oY$L
{ ~3F\7%Iqc
e.printStackTrace (); z')zVoW,
} ]0yYMnqvr
} LG6k KG
UvPD/qu$8D
//日志 XnCrxj
public static void log(String sMsg) #FL\9RXy
{ |m5 E%E
System.err.println(sMsg); fL7u419=
} v!b 8_0~u6
P O{1u%P
`4N{x.N
public static void log(int sMsg) yk<$XNc
{ @T6Z3Zj}
System.err.println(sMsg); jj&4Sv#>
} *w[\(d'T
} =e>#oPH
^twJNm{99
QxjX:O
/* aTx*6;-PH
**TestMethod.java ju= +!nGUa
*/ AHA4{Zu[
package NetFox; QlFt:?7f
xQetAYP`
V;V,G+0Re
public class TestMethod { =:;KYuTr
'\iWp?`$
cIIt ;q[
public TestMethod() Wveba)"$
{ ///xx/weblogic60b2_win.exe Z_F}Y2-w9
try{ s, 8a1o
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1`X- O>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jW G=k#WN
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y^(Sc4 W
fileFetch.start(); c T!L+zg
} l6C^,xU~IX
catch(Exception e){e.printStackTrace ();} ?5oeyBA@
N{$'-[
EpO5_T_
} rkW2_UTZE
D<m+M@u
1;4] HNI
public static void main(String[] args) !QB(M@1
{ jb~/>I^1
new TestMethod(); Viu+#J;l
} +foyPj!%
} | Ts0h?"a
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