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)); J~`%Nj5>
} $F$R4?_
for(int i=0;i<nEndPos.length-1;i++) N2Hb19/k
{ \`# 0,pLr
nEndPos = nStartPos[i+1]; HBGA lZ
} ?2>v5p
nEndPos[nEndPos.length-1] = nFileLength; .Sw'Bo!Ee
} =xP{f<`
} .Q@'Ob`
zhL,BTH
?E@[~qq_
//启动子线程 6;V1PK>9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &h[}5
for(int i=0;i<nStartPos.length;i++) p[:%Ck"$7
{ ^PpFI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BVeNK=7m%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }-iOYSn
nStartPos,nEndPos,i); kfECC&"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]`9K|v
fileSplitterFetch.start(); DMW:%h{
} (fb\A6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h%e!f#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); BBj"}~da
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C{^@.8:
nEndPos = " + nFileLength); iP_Xr~w
// fileSplitterFetch[nPos.length-1].start(); z5w|+9U
.q}k
%W@IB8]Vr
//等待子线程结束 S3wH M
//int count = 0; YNk|UwJi
//是否结束while循环 ZM!~M>B9R
boolean breakWhile = false; uMZf9XUE
W<l(C!{
brot&S2P><
while(!bStop) T6#GlO)8)
{ 11+_OC2-
write_nPos(); [)u{-
Utility.sleep(500); :E*U*#h/
breakWhile = true; NWj@iyi<
C =U4|h~W
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for(int i=0;i<nStartPos.length;i++) OO>2oH
{ pBLO
if(!fileSplitterFetch.bDownOver) *?Y6qalSy
{ 7^5BnF@
breakWhile = false; ;O>fy:$'
break; 5,Zn$zosJC
} WQ`T'k#ESW
} i(rY'o2 BN
if(breakWhile) net9KX4\
break; px@\b]/
H:6$)#
`h6W@ROb
//count++; INpub5
//if(count>4) 49GCj`As
// siteStop(); m"]ys#
} 3J<,2
{Wo7=aR
1fZ:^|\
System.err.println("文件下载结束！"); 1YL5 ![T
} bux-t3g7+
catch(Exception e){e.printStackTrace ();} L;`t%1
} JK^;-&
Y1IlH8+0
O2f2Fb$B7
//获得文件长度 fO nvC*
public long getFileSize() ;wrgpP3
{ Jmx}r,j
int nFileLength = -1; lX3h'h
try{ |e>-v
URL url = new URL(siteInfoBean.getSSiteURL()); pM3BBF%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2oLa`33c1
httpConnection.setRequestProperty("User-Agent","NetFox"); |&7,g
oJ:J'$W(
= ;d<Ikj
int responseCode=httpConnection.getResponseCode(); L4b4X
if(responseCode>=400) g!ww;_
{ cK&oC$[r-
processErrorCode(responseCode); =@o}
return -2; //-2 represent access is error %\0 Y1!Hw
} KHtY +93
AAcbY;
|#6Lcz7[
String sHeader; P_U-R%f
.<dmdqk]
4^&vRD,
for(int i=1;;i++) ev $eM
{ 5>Q)8`@E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u7d]%<~'$F
//Utility.log(in.readLine()); {,=,0NQKn
sHeader=httpConnection.getHeaderFieldKey(i); `>Cx!sYhV
if(sHeader!=null) >^&+,*tsS4
{ r8rR_M{P
if(sHeader.equals("Content-Length")) oV`sCr5%
{ T!bu}KO
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); se[};t:
break; m@YLZ
} r;z A `
} "RLb wm~
else -wB AFr
break; o*_D
} {QID@
} nKdLhCN'=
catch(IOException e){e.printStackTrace ();} Q1z04m1_y[
catch(Exception e){e.printStackTrace ();} yhaYlYv[_3
oWmla*nCKL
j7&l&)5
Utility.log(nFileLength); {Y Ymt!Ic
+zsya4r
q]x@q
return nFileLength; uc_ X;M;
} MXb(Z9)]kw
|k+^D:
pC6_ jIZ
//保存下载信息（文件指针位置） JN_# [S$
private void write_nPos() o9i\[Ul
{ GSp1,E2J
try{ e3K
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8T4J^6
output.writeInt(nStartPos.length); PJ{.jWwD
for(int i=0;i<nStartPos.length;i++) !_@%/I6
{ ~"k'T9QBY
// output.writeLong(nPos); D6w0Y:A{.
output.writeLong(fileSplitterFetch.nStartPos); 7nmo p7
output.writeLong(fileSplitterFetch.nEndPos); z( wXs&z;
} {/ta1&xyG
output.close(); '' 6
} ]NCOi?Odx
catch(IOException e){e.printStackTrace ();} F~1R.r_Lu
catch(Exception e){e.printStackTrace ();} scdT/|(U$
} E_K7.c4M
:R)IaJ6)
DI_mF#5q
//读取保存的下载信息（文件指针位置） amRtFrc|
private void read_nPos() W4<}w-AoEp
{ a|.u;
try{ )-(NL!?`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o0 Ae*Y0
int nCount = input.readInt(); < -Nj
nStartPos = new long[nCount]; l_:%?4MA
nEndPos = new long[nCount]; )7^jq|
for(int i=0;i<nStartPos.length;i++) &kG<LGXP#
{ -Q; w4@
nStartPos = input.readLong(); {-xnBx
nEndPos = input.readLong(); U^xFqJY6
} L$g;^@j
input.close(); pfT7
} (I$hw"%&
catch(IOException e){e.printStackTrace ();} :O7J9K|
catch(Exception e){e.printStackTrace ();} 6XP>p$-
} tVOx
$[Fk>d
.NKN2
private void processErrorCode(int nErrorCode) !>Xx</iD1
{ Y3[@(
System.err.println("Error Code : " + nErrorCode); + '`RJ,K+[
} CVm*Q[5s"
R:Lu)d>=
4T:ZEvdzf
//停止文件下载 4Xz|HU?
public void siteStop() <*[(t;i
{ %X3T<3<
bStop = true; MYjCxy-;A
for(int i=0;i<nStartPos.length;i++) O%Mh g\#B
fileSplitterFetch.splitterStop(); n3(HA
&\LbajP:+
tm$3ZzP4
} .MKxHM7
} Fq8Z:;C8
//负责部分文件的抓取 1WU-gQki!
**FileSplitterFetch.java y3x_B@}BY
*/ <%5ny!]
package NetFox; M<SZ7^9<
q bo`E!K
@c.pOX[]m,
import java.io.*; %lBFj/B
import java.net.*; VD4(
x-[l`k.V
!59q@Mya[
public class FileSplitterFetch extends Thread { ZR1EtvVG
6Pz\6DU,I
U-@\V1;C
String sURL; //File URL fIu/*PFPVY
long nStartPos; //File Snippet Start Position uB\A8zC
long nEndPos; //File Snippet End Position o\N),;LM
int nThreadID; //Thread's ID k20tn ew
boolean bDownOver = false; //Downing is over |K]tJi4fz
boolean bStop = false; //Stop identical y0xte&
FileAccessI fileAccessI = null; //File Access interface >">-4L17m
139_\=5|U/
^Oo%`(D?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qg_=5s
{ /wQDcz
this.sURL = sURL; {J[0UZ6
this.nStartPos = nStart; #(%6urd
this.nEndPos = nEnd; QgP UP[
nThreadID = id; ~!I \{(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z',pQ{rD
} y&UsSS
7XaRi@uG
&a V`u?'e
public void run() TV}H
{ WkT4&|POJ
while(nStartPos < nEndPos && !bStop) ;e+ErN`a.~
{ )Ipa5i>t
$(BW |Pc
DUaj]V{_^
try{ KyjN'F$
URL url = new URL(sURL); Kg56.$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &Mol8=V)
httpConnection.setRequestProperty("User-Agent","NetFox"); q:fkF^>
String sProperty = "bytes="+nStartPos+"-"; YQ]W<0(
httpConnection.setRequestProperty("RANGE",sProperty); env]*gx+=
Utility.log(sProperty); jVr:O`
=m UtBD.;
/)j:Y:5
InputStream input = httpConnection.getInputStream(); {a(TT)d
//logResponseHead(httpConnection); $. Ih-
eKt~pzXwm
PAJt M
byte[] b = new byte[1024]; %5'6^bT
int nRead; tks1*I$S<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &4LrV+`$V
{ Uo# Pe@ieQ
nStartPos += fileAccessI.write(b,0,nRead); @,$>H7o
//if(nThreadID == 1) EsdA%`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d4~!d>{n|c
} yN9/'c~
Mp}U>+8
up1kg>i%"
Utility.log("Thread " + nThreadID + " is over!"); t\ ym4`"
bDownOver = true; s~3"*,3@
//nPos = fileAccessI.write (b,0,nRead); 'bTtdFvJ
} q>t#5Z81
catch(Exception e){e.printStackTrace ();} b}WU
} @u?m4v{
} qeypa!
+Y-Gp4"
r3'0{Nn+
//打印回应的头信息 8K'3iw>z
public void logResponseHead(HttpURLConnection con) G@s rQum(
{ `#R[x7bA1
for(int i=1;;i++) 09/Mg
{ `KB;3L
String header=con.getHeaderFieldKey(i); tmKHT
if(header!=null) #mFIZMTRd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); J.$N<.
Utility.log(header+" : "+con.getHeaderField(header)); EjrK.|I0
else W|4:3c4
break; ;O+= 6>W
} nH_M#
} qf;x~1efC4
2)-Umq{]{
|cs]98FEf
public void splitterStop() 9!;/+P
{ @P@?KZ..v!
bStop = true; PKJw%.-
} dSkMA
}"Clv/3_
Qu|H_<8g
} ;0FfP
,N93H3(
$i1$nc8
/* wNtC5
**FileAccess.java -%,=%FBi~4
*//文件访问(定位，写) yw\Q>~$n[=
package NetFox; {OIB/
import java.io.*; =bgWUu\F
.~u[rc|<
DHQS7%)f`
public class FileAccessI implements Serializable{ xa8;"Y~"bg
VYbH:4K@%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^,}1^?*
RandomAccessFile oSavedFile; zcGmru|k
long nPos; TophV}@B`
zncKd{Q\tP
u.;l=tzz
public FileAccessI() throws IOException VkFMr8@|
{ cDS\=Bf
this("",0); u:.w/k%+
} -Gy=1W`09
>e^bq/'
6dgwsl~
public FileAccessI(String sName,long nPos) throws IOException y*=sboX
{ 7vTzY%v
oSavedFile = new RandomAccessFile(sName,"rw"); HA$Xg j
this.nPos = nPos; %:t! u&:q
oSavedFile.seek(nPos); j<'ftKk
} A*G ~#v^
,<k%'a!B
1%ENgb:8
public synchronized int write(byte[] b,int nStart,int nLen) L+N\B@ 0-
{ M0yv=g
int n = -1; w p\-LO~
try{ Qp7h|<
oSavedFile.write(b,nStart,nLen); 1J([*)
n = nLen; {8>g?4Q#
} D6-R>"}
catch(IOException e) >dx/k)~~-L
{ `*6|2
e.printStackTrace (); [;H-HpBaa
} kMJ}sS
$GP66Ev
60;_^v
return n; ,p{naT%R
} Dj>eAO>
djH&)&q!
}yVx"e)
} .' }jd#
O uNPDq%
?r0rY?
/* `WIZY33V
**SiteInfoBean.java 63'm @oZ
*/ 9#TD1B/
package NetFox; @R%*;)*F
tn#cVB3
fLnwA|n=
public class SiteInfoBean { 3Q'vVNFh<
l^Ob60)2
|.VSw
private String sSiteURL; //Site's URL ^s6}[LDW>@
private String sFilePath; //Saved File's Path }4N'as/ZO
private String sFileName; //Saved File's Name 8OKG@hc
private int nSplitter; //Count of Splited Downloading File qg{gCG
^D<CoxG
L&c & <+0T
public SiteInfoBean() :.4O Hp1
{//nSplitter的缺省值为5 T%% 0W J
//default value of nSplitter is 5 9dq"x[
this("","","",5); }4p)UX>aWT
} Li]bU
]!ox2m_U
VwpC UW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n&Ckfo_D
{ f`:GjA,J$
sSiteURL= sURL; -w*fS,O
sFilePath = sPath; U$mDAi$
sFileName = sName; hw,nA2w\
this.nSplitter = nSpiltter; Vm|KL3}NRv
G<M0KU(
hs[x\:})/
} y_X jY
aX`uF<c9
V:w%5'^3
public String getSSiteURL() +}O -WX?
{ 9wZ?")2
return sSiteURL; -=nk,cYn
} 5CZyA`3V^5
]Cj@",/3#
;Ax-f04gG
public void setSSiteURL(String value) \o}T0YX
{ Asv]2> x
sSiteURL = value; Ly&+m+Gwu
} ?<${?L>
)i}j\";>L
OL>)SJj5
public String getSFilePath() Qn7T{ BW
{ '{cSWa| #
return sFilePath; Rjq Xz6
} ._^}M<o L
0W(mx-[H/
][wb4$2
public void setSFilePath(String value) ]R_R`X?
{ rw,Ylr:3
sFilePath = value; ])wdd>'
} @>HTbs6W
i+h*<){X
*mzi ?3
public String getSFileName() <a]i"s
{ db~^Gqv6k
return sFileName; 5>I-? Ki
} JcWp14~e
4d`YZNvZW/
:ZM9lBYh
public void setSFileName(String value) uX*2Rs$s
{ 4~,Z 'k
sFileName = value; d #1Y^3n
} H"FK(N\
sqrLys_S
l::q F 0
public int getNSplitter() QQBh)5F
{ QkBw59L7
return nSplitter; . :Skc
} g%&E~V/g$
-NXxxK
!HvA5'|:}
public void setNSplitter(int nCount) iX$G($[l(
{ G IN|cv=
nSplitter = nCount; #B;P4n3
} P9/ (f$=
} ^+SE_-+]
7q+D}+ Xf
fZ$b8
/* T&lgWOls
**Utility.java TI'v /=;)
*/ =vbG'_[7
package NetFox; 053bM)qW
QWk3y"5n<
YIg(^>sq
public class Utility { cD0rU8x
{Sf[<I
:~otzI4%!
public Utility() LqbI/AQ)
{ vkIIuNdDlx
&"^F;z/
Ca|egQv
} E+aePoU
?H=q!i
//线程睡眠 L}`/v]E"eU
public static void sleep(int nSecond) Am<5J,<uy
{ xU.1GI%UPu
try{ fzIs^(:fl
Thread.sleep(nSecond); ; ~pgF_
} YNr"]SA@;
catch(Exception e) B&]`OO>O
{ M7TLQqaF
e.printStackTrace (); 2!{D~Gfl=
} !;eE7xn&
} ZwkUd-=0i
Cz0FA]-g
//日志 Ix-Mp
public static void log(String sMsg) J8qFdNK
{ XwY,xg&o
System.err.println(sMsg); N&HI)X2&
} >v]^nJl
iH8we,s'
wXIRn?z
public static void log(int sMsg) B*Tn@t W
{ jH< #)R
System.err.println(sMsg); 1&|]8=pG7
} {DRk{>K,
} *?FVLE
V|8'3=Z=
UxGu1a
/* (BEe^]f
**TestMethod.java YvJFZ_faX
*/ j'D%eQI,V
package NetFox; WXy8<?s
~*HQPp?v
w"j>^#8
public class TestMethod { |V a:*3u
~CNB3r5R
@G4Z
public TestMethod() ], lLDUZ\
{ ///xx/weblogic60b2_win.exe C%z)D1-
try{ #`VAw ) eV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "w:h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !"N,w9MbD
SiteFileFetch fileFetch = new SiteFileFetch(bean); B[N]=V
fileFetch.start(); 2lTt
} }J#HIE\RG
catch(Exception e){e.printStackTrace ();} _4by3?<c
zjmoIE
cYA:k
} e$[O J<t
,Y:oTo=~
,Kv6!ib6Q
public static void main(String[] args) # EvRm
{ $|~<6A{y
new TestMethod(); uj8saNu
} 287j,'vR
} ^B<-.(F
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