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)); l@h|os
} MM+xm{4l
for(int i=0;i<nEndPos.length-1;i++) &gDwsW
{ Ew&pwsQ
nEndPos = nStartPos[i+1]; *FINNNARB
} efc<lSUR
nEndPos[nEndPos.length-1] = nFileLength; P -O& X
} W-pN
} TL29{'4V
sQ)D.9\~
8RA]h?$$J
//启动子线程 ;2NJkn9t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nB~hmE)
for(int i=0;i<nStartPos.length;i++) jGeil qPC
{ a5)<roWQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?yfw3s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \),DW)
nStartPos,nEndPos,i); CQ4MQ<BJ.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 17\5NgB
fileSplitterFetch.start(); xrXfLujn%
} I3ZlKI
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }!&Vcf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E8Rk b}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ih&rXQ$
nEndPos = " + nFileLength); /K@_O\+;Q
// fileSplitterFetch[nPos.length-1].start(); q&:UP
8)NQt$lWp
" hD6Z
//等待子线程结束 feSj3,<!
//int count = 0; \V1geSoE
//是否结束while循环 F+c4v A})
boolean breakWhile = false; H*gX90{!2
3ih3O
8zOoVO
while(!bStop) DE$HF*WY
{ _#jR6g TY
write_nPos(); BE#s@-zR=p
Utility.sleep(500); o\#C#NiT
breakWhile = true; *hk8[
d,hKy2
!xIK<H{*
for(int i=0;i<nStartPos.length;i++) J&B>"s,
{ &F8N$H
if(!fileSplitterFetch.bDownOver) bh[`uRC}
{ KKCzq |
breakWhile = false; nx2iEXsa
break; vFz#A/1
} /OX;3" +1
} vC# *w,
if(breakWhile) w~3~:w$
break; y{?wxg9
JKXb$
mh4<.6>5
//count++; eB]R<a60
//if(count>4) =k{ n! e
// siteStop(); [}GPo0GY
} &ody[k?'
M9t`w-@_w
::lD7@Wg
System.err.println("文件下载结束！"); wT taj08D
} A#&,S4Wi|
catch(Exception e){e.printStackTrace ();} h&k*i
} Dh4EP/=z
'X$J+s}6&
68!W~%?pR
//获得文件长度 &4dh$w]q
public long getFileSize() kT=KxS{
{ 1luRTI8^
int nFileLength = -1; ?}n\&|+
try{ 19g-#H!
URL url = new URL(siteInfoBean.getSSiteURL()); qgk-[zW#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %VSjMZ
httpConnection.setRequestProperty("User-Agent","NetFox"); odm!}stus
{SQ#n@Q&$
d:_3V rRZ
int responseCode=httpConnection.getResponseCode(); )~Pj3
if(responseCode>=400) H2cY},
{ wH<'*>/
processErrorCode(responseCode); 8iIz!l%O
return -2; //-2 represent access is error -(Z%?]+
} 3jJd)C R
/Cl=;^)
Gy3t
String sHeader; d~>d\K%v
,WA[HwY-
H[u[3
for(int i=1;;i++) WlF}R\N!
{ m|c5X)}-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Cb1fTl%
//Utility.log(in.readLine()); l)d(N7HME
sHeader=httpConnection.getHeaderFieldKey(i); x=7qC#+)
if(sHeader!=null) Wpdn^=dhL
{ p bT sn
if(sHeader.equals("Content-Length")) ?kF_C,k/>N
{ m,qMRcDF
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0&W*U{0F\
break; x,+2k6Wn!
} )M:pg%
} 1c2zFBl.&
else n{@^ne4m
break; _P:}]5-|
} Jq1^}1P
} 9[9 ZI1*s
catch(IOException e){e.printStackTrace ();} mjI $z3
catch(Exception e){e.printStackTrace ();} U7(t >/
HXg#iP^tv
fPj*qi
Utility.log(nFileLength); 9?6]Zag
W,53|9b@
Wb;x eG
return nFileLength; k/`WfSM\.
} [3~mil3rO
0c,)T1NG>
~R$Ko(N
//保存下载信息（文件指针位置） pAY[XN
private void write_nPos() o=}vK[0u
{ yf/c
try{ Bm\OH#
output = new DataOutputStream(new FileOutputStream(tmpFile)); sT;:V
output.writeInt(nStartPos.length); !ot$Q
for(int i=0;i<nStartPos.length;i++) >~vZ+YO
{ H*H=a
// output.writeLong(nPos); _-mJI+^/
output.writeLong(fileSplitterFetch.nStartPos); Ed^F_Gg#
output.writeLong(fileSplitterFetch.nEndPos); -:P`Rln
} E979qKl
output.close(); $YPQi.
} x392uS$#
catch(IOException e){e.printStackTrace ();} jWX^h^n7K
catch(Exception e){e.printStackTrace ();} :8CYTEc
} D$vP&7pOr4
\U\k$ (
7Gs0DwV
//读取保存的下载信息（文件指针位置） ;/-X;!a>
private void read_nPos() KD*q|?Z
{ q_gsYb
try{ ,<cF<9h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &#w~S~
int nCount = input.readInt(); 1^HUu"Kt
nStartPos = new long[nCount]; Zi4Ektj2
nEndPos = new long[nCount]; !vQDPLBL
for(int i=0;i<nStartPos.length;i++) n#fc=L1U
{ &58TX[#
nStartPos = input.readLong(); QN'v]z
nEndPos = input.readLong(); %CaUC'
} I~f8+DE)
input.close(); D_(K{?KU
} 1}#RUqFrvS
catch(IOException e){e.printStackTrace ();} km[PbC
catch(Exception e){e.printStackTrace ();} 28jm*Cl8
} GO|EeM!iB
Q=!f,
2TZ+R7B?
private void processErrorCode(int nErrorCode) -y1t;yU.L
{ `JrvD
System.err.println("Error Code : " + nErrorCode); MV,;l94?%=
} noLb
!P"=57d}"l
v."0igMO
//停止文件下载 KJ]ejb$
public void siteStop() s(3iGuT
{ /EXubU73
bStop = true; {W5D)
for(int i=0;i<nStartPos.length;i++) l*0`{R
fileSplitterFetch.splitterStop(); TXDb5ZCzM
j1hx{P'
%x5zs ]4^
} [ ]LiL;A&
} j}devpO
//负责部分文件的抓取 VJ'bS9/T
**FileSplitterFetch.java <e%~K4KH
*/ H5'Le{
package NetFox; Dn9AOi!
/[|ODfY
=nTNL.SX
import java.io.*; rcyq+wY #
import java.net.*; u}L;/1,B
&8^1:CcE
GSh~j-C'
public class FileSplitterFetch extends Thread { i)[8dv
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Dqu][~oQ
String sURL; //File URL LmA IvEr
long nStartPos; //File Snippet Start Position 1X45~
long nEndPos; //File Snippet End Position SA'c}gP
int nThreadID; //Thread's ID oO8opS7F
boolean bDownOver = false; //Downing is over )b_ GKA `
boolean bStop = false; //Stop identical ::Nhs/B/
FileAccessI fileAccessI = null; //File Access interface 7Hm/g
"k%B;!We)
9"TPAywd
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #ivN-WKCl
{ `=B0NC.3
this.sURL = sURL; j& x=?jX
this.nStartPos = nStart; ;&9A Yh.
this.nEndPos = nEnd; *z{.9z`
nThreadID = id; ?7:?OX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8pQ:B/3=
} VSJ08Ngi
V,W":&!x
B,]:<1l~
public void run() ,7{}}l
{ B2uLfi$q
while(nStartPos < nEndPos && !bStop) '+Gy)@c
{ #P''+$5,
|k-IY]6
1hT!~'
try{ *Pmk1h2
URL url = new URL(sURL); Q:+cLl&;hB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OlV'#D
httpConnection.setRequestProperty("User-Agent","NetFox"); !UV/p"CfX
String sProperty = "bytes="+nStartPos+"-"; )&$Zt(
httpConnection.setRequestProperty("RANGE",sProperty); " ~X;u8m
Utility.log(sProperty); 1~x=bphS
JnT1-=t.
@}^eyS$|!
InputStream input = httpConnection.getInputStream(); TP5?%SlJ
//logResponseHead(httpConnection); )Fo1[:_B'
3X,SCG
=?, dX
byte[] b = new byte[1024]; tUp'cG
int nRead; ]DaC??%w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Y8fahQ#
{ Js7D>GWP!
nStartPos += fileAccessI.write(b,0,nRead); NSPa3NE
//if(nThreadID == 1) b[MdA|C%j
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hR]AUH
} 8O)!{gB
)= ,Lfj8x
\AT]$`8@_
Utility.log("Thread " + nThreadID + " is over!"); fy(i<L Z
bDownOver = true; nOd'$q
//nPos = fileAccessI.write (b,0,nRead); DsY$
} _cW(R,i
catch(Exception e){e.printStackTrace ();} 6.!3g(w
} H(1(H0Kj"
} t[.wx.y&0
G}lP'9/
Ofyz,% |Q
//打印回应的头信息 %Ny`d49&
public void logResponseHead(HttpURLConnection con) #xopJaY
{ ?B&@
for(int i=1;;i++) l9 |x7GB
{ l/JE}Eg(
String header=con.getHeaderFieldKey(i); <KFE.\*Z4
if(header!=null) 9J$8=UuxWG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^lP_{c
Utility.log(header+" : "+con.getHeaderField(header)); ?QnVWu2K
else SnhB$DG
break; B f_oIc
} ;bZIj`D(
} /cy'% .!
SQZUkKfb
-%U 15W;
public void splitterStop() % 1+\N
{ iE|qU_2Y
bStop = true; [;Q8xvVZ'
} 8"#Ix1#
b$24${*'
sp0j2<$a
} &tULSp@J
}Ot I8;>
G$5N8k[2
/* O>E2G]K]\
**FileAccess.java $hkMJ),T~
*//文件访问(定位，写) fDn|o"
package NetFox; o*_O1P
import java.io.*; CZ/bO#~
S[b)`Wi D
9\/T #EP
public class FileAccessI implements Serializable{ @[qGoai
Q/%(&4>'y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 EzDj,!!<w
RandomAccessFile oSavedFile; `J>76WN
long nPos; {ZS-]|Kx
&?@gUk74"
6;lJs,I1w{
public FileAccessI() throws IOException +G!N@O
{ $>3/6(bW
this("",0); #nE%.k|R~
} z|Hc=AU8y
FA.h?yfr
; )Vro
public FileAccessI(String sName,long nPos) throws IOException %0PdN@I
{ CWVCYm@!kz
oSavedFile = new RandomAccessFile(sName,"rw"); _u`NIpXSP
this.nPos = nPos; s_=/p5\
oSavedFile.seek(nPos); ~=Y<B/
} ICD(#m
hSZ0 }/
:%dIX}F
public synchronized int write(byte[] b,int nStart,int nLen) >b |TaQ
{ UC,43 z
int n = -1; -}lcMZY
try{ /`3^?zlu"
oSavedFile.write(b,nStart,nLen); )p-B@5bb
n = nLen; r@xMb,!H
} ob
catch(IOException e) v5|X=B>&>
{ kF9T 9
e.printStackTrace (); ,KlTitJl\+
} |5wuYG
g& yR-
c3gy{:lb
return n; <ByR!Y
} zfE;)K^"
aW8Bx\q
?-g=Rfpag
} OQ$77]XtvL
Jlw oSe:S
{d\erG(
/* 1n! JfsU
**SiteInfoBean.java APT'2-I_
*/ T/ CI?sn
package NetFox; s D]W/
rsP3?.E
|H.(?!nTb
public class SiteInfoBean { q|,I\H5}
rO% |PRP
?Uzs^rsb
private String sSiteURL; //Site's URL "h/{YjUS
private String sFilePath; //Saved File's Path J9oGwP
private String sFileName; //Saved File's Name f[n#Eu}
private int nSplitter; //Count of Splited Downloading File Y8I$JBO
WV5gH*uUa
ex8mA6g
public SiteInfoBean() P5ii3a?R
{//nSplitter的缺省值为5 X6mY#T'fQ
//default value of nSplitter is 5 |X9YVZC
this("","","",5); K1Tq7/N
} Eb`U^*A
A6'G%of
Urhh)i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =5EG}@
{ Ga-AhP
sSiteURL= sURL; "Hmo`EB0
sFilePath = sPath; /xjHzva^ w
sFileName = sName; J{=by]-rD,
this.nSplitter = nSpiltter; --0z"`@{
,UQ4`Mh^L
}XCHoB
} ;m}lmq,
da3]#%i0
$4`RJ{ZJw]
public String getSSiteURL() _pQ9q&i4
{ guv)[:cd;
return sSiteURL; [3s,U4a
} rMqWXGl`(
" *xQN "F
;JpU4W2/
public void setSSiteURL(String value) wobTT1!|
{ 9rX[z :
sSiteURL = value; z3b8
} od|w)?16
&yzC\XdA
x~xaE*r
public String getSFilePath() t#kR@t+6$\
{ ?Zu=UVb
return sFilePath; u0h {bu
} VAc-RaA
g% :Q86u
GmN} +(
public void setSFilePath(String value) FqiCzP4
{ w}<BO> z
sFilePath = value; 7t\W{y
} h\KQ{-Bl
]%(hZZ
:|oH11y
public String getSFileName() 3|RfX
{ )Y@
return sFileName; ^;GJ7y&,d
} ecA[
FsZF>vaV
^r^cMksB*
public void setSFileName(String value) `9eE139V='
{ \1f$]oS
sFileName = value; .l5y!?
} %"j<`
aYe,5dK>
pL>Q'{7s3
public int getNSplitter() ,;C92XY
{ Ul OoMGg
return nSplitter; +L*2 6ar6
} l%lkDh!$"
08vA;6zt
W,YzD&f=uS
public void setNSplitter(int nCount) {<&I4V@+
{ g ZhE\
nSplitter = nCount; noa?p&Y1m
} [g/Hf(&
} !1!;}uzt
\uQB%yMoz
A[v]^pv'
/* t/HMJ
**Utility.java Uf{cUY,j_
*/ QvK/31*QG
package NetFox; V{;Mh u`+
+Tde#T&[
BBnbXhxZ
public class Utility { * 4GJ<
qX`?4"4
JAen=%2b
public Utility() ?Jm/v%0O
{ ]q7\
or\ 2)
$I~=t{;"XV
} Lp20{R
_Qs)~
//线程睡眠 /s uz>o\
public static void sleep(int nSecond) e-H:;m5R
{ 25*/]iu
try{ J`;G9'n2
Thread.sleep(nSecond); ,ju1:`
} 8$-Wz:X&
catch(Exception e) MOP %vS
{ P~iu|j
e.printStackTrace (); PX52a[wNDH
} "EF:+gi#"
} A1Mr
wx BQ#OE
//日志 ^o,Hu#
public static void log(String sMsg) eI; %/6#
{ gvYa&N
System.err.println(sMsg); `,Q uO
} dgE|*1/0
.l"_f
c'&3[aa
public static void log(int sMsg) :}FMauHh
{ $jo}?Y+
System.err.println(sMsg); N \[Cuh8Fe
} Pe!uk4}w
} CT3wd?)z`
.RH}/D
x "]%q^x
/* 6cVaO@/(
**TestMethod.java e(x1w&8dB
*/ /cexd_l|f
package NetFox; 6GMQgTY^
CspY+%3$
V/$qD
public class TestMethod { .@JXV $Z
_ mhP:O
jL^zS XQB
public TestMethod() G9:[W"P
{ ///xx/weblogic60b2_win.exe prb;q~
try{ 20d[\P(.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f8+($Ys
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L{N9h1]
SiteFileFetch fileFetch = new SiteFileFetch(bean); KR%p*Nh+C
fileFetch.start(); HviL4iO
} >&RpfE[
catch(Exception e){e.printStackTrace ();} \gki!!HQ
Nj*J~&6G
U:~O^
} Xgn^)+V:
5@P2Z]Q
\;I%>yOIu
public static void main(String[] args) >e($T!}Z
{ :g}WN
new TestMethod(); Ui@Q&%b
} ,E$^i~OO
} X_Is#&6;
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