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)); YHQvx_0yP
} KJ#SE|
for(int i=0;i<nEndPos.length-1;i++) oGvk,mh"(
{ e~P4>3
nEndPos = nStartPos[i+1]; pgipT#_K
} -|g9__|@
nEndPos[nEndPos.length-1] = nFileLength; e]DuV)k&
} Bj*\)lG<
} qac8zt#2 C
H9%[! RF
cf+EQY
//启动子线程 l?<DY$H 0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'dvi@Jx
for(int i=0;i<nStartPos.length;i++) _MLbJ
{ v9 *WM3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L"Dos +
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )\RG NJMC
nStartPos,nEndPos,i); M'|?*aNK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !=bGU=^
fileSplitterFetch.start(); ;}KT 3Q<^
} XmAun
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4l rKU^-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?d' vIpzO!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U+-R2w]#q_
nEndPos = " + nFileLength); 7#+>1 "\
// fileSplitterFetch[nPos.length-1].start(); qe2@bG%2+F
/CXQ&nwY9=
}Yargj_Gn
//等待子线程结束 \]|(w*C
//int count = 0; <i~=-Z(
//是否结束while循环 !D|c2
boolean breakWhile = false; *4OB 88$
h$l`)AH^
76(/(v.x
while(!bStop) !x[].Urj
{ f<y-{.VnN$
write_nPos(); 6lob&+
Utility.sleep(500); ?M BOd9
breakWhile = true; q#PMQR"C
1YScZ
noZ!j>f{@l
for(int i=0;i<nStartPos.length;i++) SQT]'
{ l1%ubu
if(!fileSplitterFetch.bDownOver) MGLcM&oR
{ kca#ssN
breakWhile = false; /*e6('9s
break; ~?zu5,vb
} 7* R %zJ
} fLg :+Ue<B
if(breakWhile) &fe67#0r)
break; >XPR)&t
? J/NYV
G#YBfPmr
//count++; oS^g "hQ`\
//if(count>4) 6Z<|L^
// siteStop(); q+2v9K@
} js;k,`
N<~LgH
6%Pvh- ~_
System.err.println("文件下载结束！"); kgP6'`}E[
} Y?AvcY.
catch(Exception e){e.printStackTrace ();} $CDRIn50
} nhy:5eSK
t~%(Zu>S
q}gM2Ia'vY
//获得文件长度 ${{[g16X
public long getFileSize() *r)dtI*
{ I{i6e'.jP
int nFileLength = -1; E<'V6T9bi
try{ 5}TTf2&Xo#
URL url = new URL(siteInfoBean.getSSiteURL()); 2$Umqt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3,0b<vfSv
httpConnection.setRequestProperty("User-Agent","NetFox"); a7sX*5t{R
^B$cfs@*
M^{=&
int responseCode=httpConnection.getResponseCode(); 89UR w9
if(responseCode>=400) {~`{bnx^]7
{ >02p,W6S>
processErrorCode(responseCode); YBL.R;^v
return -2; //-2 represent access is error |]eWO#vs
} >{[
y*!8[wASHq
l p|`n
String sHeader; _wUg+Xs]
K0|:+s@u
Ctbc!<@o
for(int i=1;;i++) :A+}fBIN
{ 3LZvlcLb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mhI
//Utility.log(in.readLine()); {7Hc00FM
sHeader=httpConnection.getHeaderFieldKey(i); -s^)HR l
if(sHeader!=null) d%:J-UtG"
{ Y/T-2)D
if(sHeader.equals("Content-Length")) @<koL
{ \|C*b<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T0N6k acl
break; wW7#M
} e4FR)d0x
} aH\A
else 3Xm> 3
break; a5pXn v]A
} ;Irn{O
} @M6F?;
catch(IOException e){e.printStackTrace ();} :qj7i(
catch(Exception e){e.printStackTrace ();} h0")NBRV&
pGr4b:N
,I H~
Utility.log(nFileLength); vCUbbQz
7n*"9Ai(
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return nFileLength; "A0y&^4B@
} ,z#S=I
0,B"p
.:O($9^Ho
//保存下载信息（文件指针位置） :r7!HG_
private void write_nPos() !Y 9V1oVf"
{ 7bQST0?
try{ T1%}H3
output = new DataOutputStream(new FileOutputStream(tmpFile)); xT-`dS0u
output.writeInt(nStartPos.length); ^O!;KIe{g
for(int i=0;i<nStartPos.length;i++) TLq^5,qG
{ 6?a z
// output.writeLong(nPos); Zr(eH2}0D
output.writeLong(fileSplitterFetch.nStartPos); eQ*zi9na
output.writeLong(fileSplitterFetch.nEndPos); gHFQs](G.
} rDGrq9
output.close(); JAy-N bb\
} v6ei47-
catch(IOException e){e.printStackTrace ();} n<1*cL:8B
catch(Exception e){e.printStackTrace ();} D^6Q`o
} jp|*kBDq\
4I#@xm8)
h]/3doP
//读取保存的下载信息（文件指针位置） gAgF$H .
private void read_nPos() E=91k.
{ \Nk578+AA
try{ 3R)|DGql=1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )4N1EuD6
int nCount = input.readInt(); 7g:Lj,Z4L
nStartPos = new long[nCount]; -@@ O<M^
nEndPos = new long[nCount]; IaKJ W?
for(int i=0;i<nStartPos.length;i++) s1tkiX{>
{ dptfIBYc+
nStartPos = input.readLong(); !x!1H5"
nEndPos = input.readLong(); bXA%|7*
} K"ly\$F
input.close(); @>&b&uj7T
} /qFY$vj
catch(IOException e){e.printStackTrace ();} = ?BhtW
catch(Exception e){e.printStackTrace ();} E{}J-_oS45
} ^Jw=5ImG
r;p@T8k
o#WECs>
private void processErrorCode(int nErrorCode) (M<l}pl)
{ gf}*}8D
System.err.println("Error Code : " + nErrorCode); ;@ G^eQ
} egH,7f(yP
Y#+Ws0wN
S(/^_Y
//停止文件下载 y}?PyPz
public void siteStop() [("2=Uz;
{ .m.Ga|;
bStop = true; wc-v]$DW
for(int i=0;i<nStartPos.length;i++) Ai)>ot
fileSplitterFetch.splitterStop(); FjMKb
%:j`%F;R
9W,%[
} j& ykce
} h!Y##_&&4
//负责部分文件的抓取 3i\Np =
**FileSplitterFetch.java 9|Ylv:sR
*/ |nm}E_
package NetFox; 3Pp+>{2_?
Wf-XH|j[
\.>7w 1p
import java.io.*; <"}t\pT]
import java.net.*; iP@FXJJ
CugZ!>;^
?9>wG7cps7
public class FileSplitterFetch extends Thread { ]68FGH
`\'V]9wS
PHJHW#sv
String sURL; //File URL OUFy=5(%:
long nStartPos; //File Snippet Start Position G6lC[eK
long nEndPos; //File Snippet End Position F_I!qcEQ
int nThreadID; //Thread's ID \<dg
boolean bDownOver = false; //Downing is over "zkQu
boolean bStop = false; //Stop identical $zF%F.rln
FileAccessI fileAccessI = null; //File Access interface l]j;0i
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Q [C26U
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $$EEhy
{ |'I>Ojm
this.sURL = sURL; KW3<5+w]c
this.nStartPos = nStart; <L<^uFB
this.nEndPos = nEnd; O#p_rfQ
nThreadID = id; 9XKqsvdS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5ArgM%
} PKC0Dt;F.
VMe
?$qA+iP0
public void run() _+Sf+ta
{ o^Lq8u;i*
while(nStartPos < nEndPos && !bStop) E" >`
{ oE6`]^^
7WY~v2SDF
1Kr$JIcd
try{ z30 mk
URL url = new URL(sURL); EUVD)+it
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :U/]*0b
httpConnection.setRequestProperty("User-Agent","NetFox"); #Ma:Av/ )
String sProperty = "bytes="+nStartPos+"-"; !0P:G#o-$
httpConnection.setRequestProperty("RANGE",sProperty); sI h5cT
Utility.log(sProperty); Ul6|LTY
[zXC$&!
Gt _tL%
InputStream input = httpConnection.getInputStream(); q'4P/2)va
//logResponseHead(httpConnection); fD3'Ye<R
^,FG9
z]-m<#1
byte[] b = new byte[1024]; &328pOT4
int nRead; "6U@e0ht
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <QC7HR
{ uPapINj
nStartPos += fileAccessI.write(b,0,nRead); &:u3-:$:9
//if(nThreadID == 1) #I*{_|}=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9Kgyt
} *SIYZE'
Vh2uzG
>B=s+}/ME
Utility.log("Thread " + nThreadID + " is over!"); 7l[@c|e
bDownOver = true; i$`o,m#
//nPos = fileAccessI.write (b,0,nRead); 12?!Z
} wa{!%qu5.R
catch(Exception e){e.printStackTrace ();} +a%D+
} {MyI3mvA
} 5k9 vYW5k
%NJ0Y(:9(
G-|c%g!ejf
//打印回应的头信息 *uf)t,%
public void logResponseHead(HttpURLConnection con) >;R`Q9s7
{ .MRN)p
for(int i=1;;i++) 5f?GSHA}
{ *W`7JL,
String header=con.getHeaderFieldKey(i); uv8kea .(
if(header!=null) +P Dk>PdEt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RAk"C!&^m
Utility.log(header+" : "+con.getHeaderField(header)); HV-;?5
else I8% -ii
break; WTM
} eThFRU3 F
} Nnr[@^M5
_+nk3-yQw
'+ZJf&Ox
public void splitterStop() *s-s1v
{ rx 74v!
bStop = true; 'DNxc
} IVZUB*wv)b
<DPRQhNW]
jkta]#O
} 6<>1,wbq
}{j@q~w>$
Mis B&Ok`k
/* i$$h6P#
**FileAccess.java }9W[7V?
*//文件访问(定位，写) Vdefgq@<
package NetFox; hkm}oYW+
import java.io.*; %&VI-7+K
(n~fe-?}8
XP0;Q;WF}
public class FileAccessI implements Serializable{ 7l/lY-zO
0Z]HH+Z;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T3<1{"&
RandomAccessFile oSavedFile; CGlEc
long nPos; s!
&A.0(s
wIR"!C>LE
public FileAccessI() throws IOException reArXmU<u
{ hmOGteAf-
this("",0); J Eo;Fx]
} vnVT0)Lel
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"S6";G^I
public FileAccessI(String sName,long nPos) throws IOException zLJmHb{(
{ Zi7cp6~7
oSavedFile = new RandomAccessFile(sName,"rw"); OIpT9
this.nPos = nPos; \'[tfSB
oSavedFile.seek(nPos); Ii5U)"
} [7HBn
1 I.P7_/
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public synchronized int write(byte[] b,int nStart,int nLen) FXn98UFY
{ "4Q_F3?_`
int n = -1; r-L& ee
try{ L@=$0p41;
oSavedFile.write(b,nStart,nLen); #Y3-P
n = nLen; b=\chCRJJ
} WQ8 "Jj?k6
catch(IOException e) @x}^2FE
{ *`wz
e.printStackTrace (); nw+^@|4
} C96*,.j~'
p=A,yGDV
7RBEEE`)
return n; (3D&GY!/
} Ab/JCZNn
0gW{6BtPWm
3h>L0
} H~vrCi~t"
%,z;W-#gnY
4%8den,|
/* ?E+f<jol
**SiteInfoBean.java u kZK*Y9P
*/ ]Q0bL
package NetFox; %xG<hNw/
nh5=0{va|L
_izjvg
public class SiteInfoBean { g]}!
bHx@
tJ6Q7 J;n
private String sSiteURL; //Site's URL ~8mz.ZdY
private String sFilePath; //Saved File's Path hgW1g#
private String sFileName; //Saved File's Name `[#id@Z1
private int nSplitter; //Count of Splited Downloading File ]1>R8
TIl 'Z7
4@Db $PHs
public SiteInfoBean() ;L-)$Dy4
{//nSplitter的缺省值为5 WwZ3hd
//default value of nSplitter is 5 s$fX ;
this("","","",5); Ai[@2AyU
} K$qY^oyQFw
Me?I8:/
k[D,du')
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) jVN06,3z
{ #|(>UM\
sSiteURL= sURL; Z : xb8]y
sFilePath = sPath; G'}N?8s1
sFileName = sName; Pp8G2|bz
this.nSplitter = nSpiltter; z_R^C%0k
)D/,QWk
w}OBp^V^
} _4L6
5fiWo^s}
%bF157X5An
public String getSSiteURL() ercXw7{
{ LS9,:!$
return sSiteURL; I}|a7,8
} *VJISJC
iEr?s-or
ilJ`_QN
public void setSSiteURL(String value) g~.#.S ds
{ *<67h*|)
sSiteURL = value; r5nHYV&7
} gYrB@W;2
FNF`Z
N*&T)a
public String getSFilePath() \ HUDZ2 s
{ wf]?:'}
return sFilePath; ]4[%Sv6]G
} 2#^g] o-N
_z BfNz9D
Q Kr/
public void setSFilePath(String value) ^JMG'@x
{ |,oLZCNa
sFilePath = value; T!y 9v5
} EwV$2AK
H,GjPIG
9d/-+j'
public String getSFileName() \a|~#N3?
{ lGR0-Gh2
return sFileName; bsU$$;
} $<2d|;7r
2 G*uv+=
aAGV\o{^
public void setSFileName(String value) e<9 ^h)G
{ I2i'
sFileName = value; 7* Y*_cH5
} 5rck]L'
|36%B7H
d;gs1]E50
public int getNSplitter() gU|:Y&lFZg
{ ~!5Qb{^
return nSplitter; H9ES|ZJs
} 579D
\WC,iA%Y
+CdUr~6
public void setNSplitter(int nCount) e_|<tYx><
{ 985h]KQ
nSplitter = nCount; v.C
} "PRHQW
} 8M,o)oH
~?aFc)
A~nqSe
/* sPW:[
**Utility.java :P2!& W
*/ <^5$))r
package NetFox; NI,>$@{
8[X"XThj
9%NsW3|
public class Utility { zo"L9&Hzo
gvWgw7z
/LWk>[Z;
public Utility() +<p&Va#
{ 6AY(/N8V
L7(FDv,?
e/+.^ '{
} t(roj@!x_o
+3zQ"lLD^
//线程睡眠 [DeDU:
public static void sleep(int nSecond) Ty{ SZUJ
{ Q) aZ0 Pt
try{ ,|VLOY^
Thread.sleep(nSecond); PH8 88O
} nZ'jjS[!
catch(Exception e) Nk\ni>Du3
{ H#YI7l2
e.printStackTrace (); /"A=Yf
} ai?J
} 9RJ#zUK
oVHe<zE.
//日志 `G:1
public static void log(String sMsg) P#!gP3
{ m5N,[^-
System.err.println(sMsg); )ADI[+KW
} _MIheCvV
:'<;]~f
s Y1@~v
public static void log(int sMsg) fOSk> gK
{ ]C"?xy
System.err.println(sMsg); )ej1)RU"
} Hk4k
} |H^v8^%>zm
nxuH22:
.K4)#oC
/* T`]%$$1s
**TestMethod.java _qf~ hhi
*/ `0U\|I#
package NetFox; nTGf
F?a 63,r
"pK<d~Wu
public class TestMethod { 2Uf/'
%?+Lkj&
!a\v)R
public TestMethod() zTMLE~w
{ ///xx/weblogic60b2_win.exe &Lzd*}7
try{ T'lycc4~a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SOsz=bVx
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (m!kg
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5 Slz^@n
fileFetch.start(); x5\Du63
} a;; Es
catch(Exception e){e.printStackTrace ();} M'R ] ''
~QUNR?h
Sw>>]UjU
} rt*>)GI]b
5o4KV?"
b1'849i'y=
public static void main(String[] args) `IBNBJy
{ kUGFg{"
new TestMethod(); GL9'dL|
} d#d&CJAfr
} lcpiCZ
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