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)); ':\bn:;
} wB[ JFy"E
for(int i=0;i<nEndPos.length-1;i++) Bbb":c6w0
{ t >64^nS
nEndPos = nStartPos[i+1]; _-v$fDrz
} %6V=G5+W
nEndPos[nEndPos.length-1] = nFileLength; n0':6*oGW
} $b_~
} ^h`rA"F\
Ms%C:KG
t08[3Q&
//启动子线程 8_rd1:t5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -=u9>S)!c
for(int i=0;i<nStartPos.length;i++) ^#w9!I{4.
{ .lz=MUR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {@" F/G+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O15~\8#'
nStartPos,nEndPos,i); _|{pO7x]oG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7{rRQ~s&g9
fileSplitterFetch.start(); PIsXX#`7;
} VdL }$CX$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UG]5Dxk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ej(w{vl
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Sc]h^B^7
nEndPos = " + nFileLength); q^[SN
// fileSplitterFetch[nPos.length-1].start(); IPY[x|
RHt~:D3*
.MxMBrM
//等待子线程结束 eX^ F^(
//int count = 0; H Mfhe[A?
//是否结束while循环 'EU|w,GL}
boolean breakWhile = false; -K5u5l}
s*kSl:T@O
3"6-X_
while(!bStop) Op iVQr:
{ ixF
write_nPos(); \#'m([<e
Utility.sleep(500); !h*F58
breakWhile = true; g$Nsu:L
wH qbTA
tlmfDQD
for(int i=0;i<nStartPos.length;i++) &<5oDdC
{ wpJfP_H
if(!fileSplitterFetch.bDownOver) iM{aRFL
{ $K~ t'wr
breakWhile = false; Y&*nj`n
break; _ 3jY,*
} 0^ $6U
} ::k/hP9.^
if(breakWhile) R<8!lQ4s
break; &qeMYYY
^:m7Qd?Z[
)u5+<OG}=
//count++; ->U9u lTC
//if(count>4) \&X*-T[]j
// siteStop(); !bIhw}^C*
} !W45X}/o
G9a6 $K)b
Ha20g/UN.
System.err.println("文件下载结束！"); H5p&dNO
} >[gNQJ6
catch(Exception e){e.printStackTrace ();} g E;o_~
} I>3]VRi
/%T d(
=!|=Y@
//获得文件长度 c7(Lk"G8
public long getFileSize() %u02KmV.
{ -85W/%
int nFileLength = -1; kG$U
try{ A"~4|`W
URL url = new URL(siteInfoBean.getSSiteURL()); O0,=@nw8.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,[<+7
httpConnection.setRequestProperty("User-Agent","NetFox"); c0u1L@tj
xnD"LK
eww/tGa
int responseCode=httpConnection.getResponseCode(); u~q6?*5
if(responseCode>=400) rRzc"W}K+
{ "s5[w+,R
processErrorCode(responseCode); rWB/#m
return -2; //-2 represent access is error i-*ZW:
} }IGoPCV|
_Kf8,|+
?."YP[;
String sHeader; Y('?Z]
MGE8S$Z
c 1o8
for(int i=1;;i++) XPQY*.l&.
{ n!$zO{P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .DG`~Fpk
//Utility.log(in.readLine()); w9]HJ3qi
sHeader=httpConnection.getHeaderFieldKey(i); ;G|#i?JJ
if(sHeader!=null) x,:DL)$1
{ Dlqvz|X/
if(sHeader.equals("Content-Length")) Zb}U 4
{ P}8cSX9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); IB\O[R$x
break; (utk)
} Q"F" 13
} ~KP@wD~
else )/cf%
break; hh7unHt-
} 92XG|CWX
} Cm%|hk>fQ
catch(IOException e){e.printStackTrace ();} #sM`>KG6T1
catch(Exception e){e.printStackTrace ();} x@#aOf4<U
xVN(It7g
-]<<}@NF
Utility.log(nFileLength); s a{x.2/o}
"DvhAEM
H7%q[O
return nFileLength; D=@bPB>
} e?_uJh"
H/}W_ h^^
V@o#" gZ
//保存下载信息（文件指针位置） oLIgj,k{*
private void write_nPos() EslHml#
{ O-&^;]ieJ
try{ ]w_JbFmT
output = new DataOutputStream(new FileOutputStream(tmpFile)); T~8kKw
output.writeInt(nStartPos.length); @%BsQm
for(int i=0;i<nStartPos.length;i++) z1nKj\AM2
{ XaF;IS@A
// output.writeLong(nPos); >|aVGY
output.writeLong(fileSplitterFetch.nStartPos); Fv<3VKueK[
output.writeLong(fileSplitterFetch.nEndPos); 5Nl?Km~
} b_f"(l8'S
output.close(); y({lE3P
} I,W`s
catch(IOException e){e.printStackTrace ();} Y<h6m]H
catch(Exception e){e.printStackTrace ();} >i"WKd=
} *alifdp
+GncQs y
Pk>S;KT.
//读取保存的下载信息（文件指针位置） n0Qp:_2z
private void read_nPos() _Kbj?j
{ >XxHp
try{ ^l<!:SS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~r_2V$sC2
int nCount = input.readInt(); kB.CeG]tk
nStartPos = new long[nCount]; 4~Y?*|G]m
nEndPos = new long[nCount]; $+PyW( r
for(int i=0;i<nStartPos.length;i++) ^#IE t#
{ Z1Qv>@u
nStartPos = input.readLong(); vCXmu_S4^>
nEndPos = input.readLong(); j^WYMr,
} `F]
input.close(); m41%?uC/
} N.0g%0A.D
catch(IOException e){e.printStackTrace ();} @vB-.XU
catch(Exception e){e.printStackTrace ();} ahQY-%>
} B]vR=F}*
mkhWbzD'S
0X4)=sJP
private void processErrorCode(int nErrorCode) CO9PQ`9+
{ mHV{9J
System.err.println("Error Code : " + nErrorCode); "vg.{
} z~==7:Os
E-($Xc
d!4TwpIgx
//停止文件下载 QBGjH^kL
public void siteStop() .YWkFTlZ+
{ `SOQPAnK+;
bStop = true; |a a\t
for(int i=0;i<nStartPos.length;i++) seRf q&
fileSplitterFetch.splitterStop(); ,RM8D)m\
#p7gg61
cTS.yN({G
} <QO1Yg7}
} REYvFx?i
//负责部分文件的抓取 ck%YEMs
**FileSplitterFetch.java Tl'wA^~H
*/ LnKgT1
package NetFox; wu><a!3`=o
FRajo~H
0[M2LF!m
import java.io.*; 6)*B%$?x
import java.net.*; )Tp"l"(G
@;$cX2
3;VH'hh_
public class FileSplitterFetch extends Thread { g1}:;VG=
?|/K(}
^_g%c&H
String sURL; //File URL :o8|P
long nStartPos; //File Snippet Start Position f6yj\qq]
long nEndPos; //File Snippet End Position 0nL #-`S
int nThreadID; //Thread's ID 71Za!3+
boolean bDownOver = false; //Downing is over |JF,n~n
boolean bStop = false; //Stop identical U,Uy0s2r
FileAccessI fileAccessI = null; //File Access interface D)?%kNeA
{9-9!jN{"
(H&HSs
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?jUgDwc(w
{ ZOcpF1y
this.sURL = sURL; 8<mloM-4
this.nStartPos = nStart; 9#:fQ!3`
this.nEndPos = nEnd; az:}RE3o
nThreadID = id; >l><d!hw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yo->mD
} DbLo{mFEIj
R!QR@*N
JbL3/h]
public void run() 036m\7+Qj
{ (lS[a
while(nStartPos < nEndPos && !bStop) gaz",kK<
{ `^[Tu 1
V0Oqq0\
fdX|t"oz
try{ 8 yi#] 5`Q
URL url = new URL(sURL); >'W,8F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A+8)VlE\
httpConnection.setRequestProperty("User-Agent","NetFox"); "qF/7`e[
String sProperty = "bytes="+nStartPos+"-"; h)ZqZ'k$
httpConnection.setRequestProperty("RANGE",sProperty); 6xtgnl#T
Utility.log(sProperty); COu5Tu^
21tv(x
<=GZm}/]N
InputStream input = httpConnection.getInputStream(); IB|6\uKn
//logResponseHead(httpConnection); &U?4e'N)T
zJW2F_
MXfyj5K
byte[] b = new byte[1024]; g[1>|Ax`'
int nRead; aReJ@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7F0J*M
{ )Cj1VjAg
nStartPos += fileAccessI.write(b,0,nRead); tmq?h%O>
//if(nThreadID == 1) og35Vs0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EK=0oy[
} ru2M"]T
9%|skTgIqH
!KOa'Ic$V
Utility.log("Thread " + nThreadID + " is over!"); z"yW):X
bDownOver = true; Miw=2F
//nPos = fileAccessI.write (b,0,nRead); ],0I`!\
} R/"-r^j
catch(Exception e){e.printStackTrace ();} K/Yeh<_&
} R|8L'H+1x
} (0Br`%!F
X)hpbHa
rn( drG
//打印回应的头信息 2;"vF9WMm
public void logResponseHead(HttpURLConnection con) 6M7GPHah
{ N atC}k
for(int i=1;;i++) 1G12FV>M
{ 3bezYk
String header=con.getHeaderFieldKey(i); =dHdq D
if(header!=null) +JC"@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9-{+U,3)
Utility.log(header+" : "+con.getHeaderField(header)); @0PWbs$
else v\8v'EDP
break; tlD^"eq4:
} /v<Gt%3X
} iOhX\@&
\F`>zY2$%
~E8/m_> rU
public void splitterStop() ,7s+-sRG
{ 6l2O>V
bStop = true; Wd!Z`,R
} k=kkF"
v)O].Hd
n(#yGzq
} `a[fC9
zQ,M795@EA
vv2[t
/* E A55!
**FileAccess.java X=f%!
*//文件访问(定位，写) vs+aUT C\
package NetFox; `5oXf
import java.io.*; 4zhh**]B
C:sgT6
?RsPAL
public class FileAccessI implements Serializable{ p>J@"?%^
6A=k;do
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N$t<&5+
RandomAccessFile oSavedFile; LcA7f'GVK
long nPos; <3j`Z1J
x<rS2d-Y
t OJyj49^a
public FileAccessI() throws IOException j-"34
{ N8kNi4$mp=
this("",0); 2/A*\
} =~W=}
nvwf!iU6
^C~R)M:C
public FileAccessI(String sName,long nPos) throws IOException j$s/YI:
{ WPpO(@sn
oSavedFile = new RandomAccessFile(sName,"rw"); #ucb
this.nPos = nPos; 8b-mW>xsA
oSavedFile.seek(nPos); %LmsywPPp
} P4{~fh(
b+arnKo1fk
A1Uy|Dl
public synchronized int write(byte[] b,int nStart,int nLen) kMLJa=]$
{ Gl|n}wo$
int n = -1; #l- 0$
try{ S#yGqN0i
oSavedFile.write(b,nStart,nLen); @VG@|BQWa
n = nLen; |dqESl,2
} dXM8iP
catch(IOException e) 0nkC%j
{ P{QHG 3
e.printStackTrace (); ?GhMGpdMq
} {{M/=WqC
v)gMNzt
-$g~,dIwj
return n; #%E^cGfY
} P?|\Ig1Gk
3pW4Ul@e
#QcRN?s
} ns\I Y<Yo
Hsv)] %p
j[w=pF,o
/* -gt?5H h
**SiteInfoBean.java L%\Wt1\[
*/ m2l9([u=^
package NetFox; 1t^9.!$@y
]e"!ZR?XJ
LdNpb;*
public class SiteInfoBean { \SO)|M>.a
'yA/sZ
~$[fG}C.K
private String sSiteURL; //Site's URL -gba&B+D"
private String sFilePath; //Saved File's Path Tl[*(|/C
private String sFileName; //Saved File's Name h2Th)&Fb>
private int nSplitter; //Count of Splited Downloading File 0pEM0M
tH *|
.{`C>/"}
public SiteInfoBean() pO:]3qv
{//nSplitter的缺省值为5 A4#FAFy
//default value of nSplitter is 5 PO6yEr
this("","","",5); tAJ}36aG
} ~re}6-?
GQA\JYw|oY
6hYz^}2g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '2<r{
{ (6a<{
sSiteURL= sURL; +By'6?22
sFilePath = sPath; i}v.x
sFileName = sName; ZxT E(BQv
this.nSplitter = nSpiltter; CZeZk
62_k`)k
l*&N<Yu
} Kn@#5MC rU
H2#o X
g9VY{[V
public String getSSiteURL() $m*Gu:#xm&
{ NjEi.]L*fX
return sSiteURL; s9nPxC&A
} {R@V
"uIaKb
Fc\]*
public void setSSiteURL(String value) 0\ (:y^X
{ /PTRe5-7
sSiteURL = value; LOfw #+]d
} V8B4e4F
<n#X~}i)
-XV+F@`Md
public String getSFilePath() YkB@fTTS
{ *.|%uf.
return sFilePath; {b4`\I@<
} ml1%C%
!R\FCAW[x
$'Mf$h
public void setSFilePath(String value) +#BOWz
{ QNU~G3
sFilePath = value; ]gcOMC
} 0]c&K
r W[;3yMf
miQ*enZi
public String getSFileName() o|z@h][(l(
{ wxh\CBxG
return sFileName; UiH7
} a6DR' BC
QE[<Y3M
<Jhd%O
public void setSFileName(String value) }5oI` 9VT
{ OR~ui[w
sFileName = value; lRg?||1ik
} #vV]nI<MF.
A[;deHg=
vQi=13Pw
public int getNSplitter() 5<ruN11G
{ Y#68_%[
return nSplitter; n Ab~
} &F~d~;G"q
\vT~2Y(K
<5z!0m-G
public void setNSplitter(int nCount) ^*.$@M
{ VM\R-[
nSplitter = nCount; <>\|hno}
} raPOF6-_rH
} J Ah!#S(
8~C}0H
*GE6zGdN
/* !s=$UC
**Utility.java C 6 \
*/ Ie^Ed`
package NetFox; :zKW[sF
:gwmk9LZ
?tjEXg>ny
public class Utility { (rBsh6@)
cl^UFlf[
%@a;q?/?Nd
public Utility() 9S]pC?N]E
{ ^vd$j-kjTP
}=bzUA`C
2T2<I/")O
} (v/L
^R@)CIQ
//线程睡眠 pE<a:2J
public static void sleep(int nSecond) fL2P6N@
{ " C0[JdZ
try{ $EFS_*<X
Thread.sleep(nSecond); C:Rs~@tl
} geyCS3 :p
catch(Exception e) .Bl:hk\
{ jV*10kM<
e.printStackTrace (); LD[\eJ_
} 45.ks.
} md{nHX&
?pEPwc
//日志 rogy`mh\r2
public static void log(String sMsg) r[Pp[g-J
{ O.Pp*sQ^
System.err.println(sMsg); 85&7WAco"B
} UiV#w#&P
3<XuJ1V&
Nxe1^F33
public static void log(int sMsg) L-?ty@-i
{ +C!GV.q[
System.err.println(sMsg); WZ?>F
} ~2rQ80_
} F?2UHcs
*RS/`a;,
}'wZ)N@
/* ?=Ceo#Er
**TestMethod.java ((]i}s0S
*/ Ich^*z(F$
package NetFox; M2cGr
cu>(;=
)@DDs(q=i
public class TestMethod { 5;KJ0N*-
&mtt,]6C_
{?lndBP<
public TestMethod() }d;2[fR)
{ ///xx/weblogic60b2_win.exe J(}PvkA
try{ $`GlXiV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LGuZp?"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $Z)u04;&@
SiteFileFetch fileFetch = new SiteFileFetch(bean); Szt2 "AR
fileFetch.start(); ^=^\=9" b
} `oNJ=,p
catch(Exception e){e.printStackTrace ();} 4Lg ,J9
9l~D}5e7
1A'eH:$
} bj@sci(1?
a6vej
!0lk}Uzkh
public static void main(String[] args) C[%Qg=<
{ M`al~9
new TestMethod(); D*2*FDGI
} J/P[9m30[
} V/H+9+B7Im
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