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)); CZfE |T~
} %O/d4
for(int i=0;i<nEndPos.length-1;i++) RHXvee55
{ {]M>Y%j48
nEndPos = nStartPos[i+1]; Ws>i)6[
} <_f`$z
nEndPos[nEndPos.length-1] = nFileLength; uRGB/ju^E
} \-G5l+!
} O*4gV}:G
CK Mv7
tGqQJT#mr7
//启动子线程 .~22^k
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )rbc;{.
for(int i=0;i<nStartPos.length;i++) zf7rF}
{ TnxU/)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 44<v9uSK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E- KK
nStartPos,nEndPos,i); <>&89E%j'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [>wzl"cHW
fileSplitterFetch.start(); b_l.QKk
} uegb;m
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =<>pKQ)[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `%%?zgY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", aulaX/'-_
nEndPos = " + nFileLength); <%/:w/
// fileSplitterFetch[nPos.length-1].start(); gTuX *7w
G ;jF9i
oX#9RW/ >I
//等待子线程结束 { $X X
//int count = 0; LEA;dSf
//是否结束while循环 H}(=?}+
boolean breakWhile = false; dJaEoF
B'!PJj
0|GpZuGO9
while(!bStop) E2-ojL[6
{ G u6[{u
write_nPos(); >|5XaaDa
Utility.sleep(500); Sr-|,\/O
breakWhile = true; |zT%$
0&f\7z
}]tFz}E\
for(int i=0;i<nStartPos.length;i++) $e>/?Ss
{ xa' nJ"f;
if(!fileSplitterFetch.bDownOver) S\}?zlV
{ HKM~BL "X
breakWhile = false; FBYll[8
break; R9bhC9NP
} $R8>u#K!
} `B:B7Cpvn
if(breakWhile) 5DmCxg
break; Ck:#1-t8{
`:V}1ioX5
_s2m-jm7
//count++; ^}>zYt
//if(count>4) poTl|y @
// siteStop(); zoJ_=- *s
} h=!M6yap<
f<'n5}{RO0
=DGn,i9
System.err.println("文件下载结束！"); pCz@(:0
} ~*jsB=XM/
catch(Exception e){e.printStackTrace ();} w:ORmR.p
} 1 ,#{X3
+Gk! t]dy
UY1JB^J$
//获得文件长度 ~8XX3+]z:X
public long getFileSize() tZdwy>;
{ %~][?Y ><
int nFileLength = -1; pQk=x T
try{ <WZ1-
URL url = new URL(siteInfoBean.getSSiteURL()); i7i|370
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }pbBo2
httpConnection.setRequestProperty("User-Agent","NetFox"); IOSuaLH^
V?U%C%C|e
P%.`c?olbs
int responseCode=httpConnection.getResponseCode(); [?Mc4uT{
if(responseCode>=400) |h#DL$
{ 83{x"G3>
processErrorCode(responseCode); $ /}:P
return -2; //-2 represent access is error l81&[
} #[gcg]6c
ipx@pNW;"
:5TXA
String sHeader; zAKq7'_=
nQ:ml
C1ZFA![
for(int i=1;;i++) tqff84
{ l-DGy#h+z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?&whE!
//Utility.log(in.readLine()); o|rGy5
sHeader=httpConnection.getHeaderFieldKey(i); K[iY{
if(sHeader!=null) \SYPu,ZT
{ &,m'sQ
if(sHeader.equals("Content-Length")) y8<lp+
{ :J=+;I(UI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); IgzCh
break; *b$z6.
} xHM&csL
} iFAoAw(
else "-0pz\a
break; kr/1Dsr4
} "Cb.cO$i;
} e.3sAUHZ-
catch(IOException e){e.printStackTrace ();} oiTMP`Y
catch(Exception e){e.printStackTrace ();} RT.wTJS;
|x _-I#H
J9b?}-O)
Utility.log(nFileLength); >.!5M L\
S7Iu?R_I
~aauW?
return nFileLength; +WV_`Rx#
} k$UzBxR
Lyf? V(S
P-E'cb%ub
//保存下载信息（文件指针位置） Rk437vQD,
private void write_nPos() `>`K7-H
{ r|JiGj^om
try{ s60:0>
output = new DataOutputStream(new FileOutputStream(tmpFile)); :oon}_MdRd
output.writeInt(nStartPos.length); ^B&ahk
for(int i=0;i<nStartPos.length;i++) <6}f2^
{ `aO@N(
// output.writeLong(nPos); (IoPU+1b
output.writeLong(fileSplitterFetch.nStartPos); SBN_>;$c5}
output.writeLong(fileSplitterFetch.nEndPos); Sob $j
} pb/{ss+
output.close(); zP{<0o
} 5ykk11!p$
catch(IOException e){e.printStackTrace ();} 6'No4[F 4n
catch(Exception e){e.printStackTrace ();} fo!Lp*'0
} =7J|KoKK
[c KI0
`:bvuc(
//读取保存的下载信息（文件指针位置） l_YdIUl
private void read_nPos() z2s|.M]&-D
{ (4{@oM#H6
try{ {>UMw>T[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o7@4=m}
int nCount = input.readInt(); -}N\REXE
nStartPos = new long[nCount]; qy42Y/8'
nEndPos = new long[nCount]; @E"+qPp.3
for(int i=0;i<nStartPos.length;i++) p^zEfLTU
{ =-Q
nStartPos = input.readLong(); #*>7X>,J
nEndPos = input.readLong(); _OknP2E
} xV n]m9i
input.close(); =:n[{/O=
} Og;$P'U
catch(IOException e){e.printStackTrace ();} vRb(eg
catch(Exception e){e.printStackTrace ();} YnO1Lf@
} !/(}meZj
|b;M5w?
H=BR -
private void processErrorCode(int nErrorCode) Vq7 kA "
{ \w_[tPz}
System.err.println("Error Code : " + nErrorCode); r~Ubgd ]U
} ]:#$6D"
PaeafL65=
d\Z4?@T<5
//停止文件下载 ZXDMbMD
public void siteStop() :8L61d2(
{ ?&nz
bStop = true; 6)<oO(
for(int i=0;i<nStartPos.length;i++) \*"0wR;[K
fileSplitterFetch.splitterStop(); Fl>j5[kLZ
1'pQ,
z}N^`_ *
} s ;Nu2aOp7
} AX Jj"hN
//负责部分文件的抓取 `/Jr8J_
**FileSplitterFetch.java v=WDs#"
*/ 0 S8{VZpy
package NetFox; ';!UJWYl
4i&!V9@:
,^66`C[G
import java.io.*; {cHTg04
import java.net.*; )4~XZt1r
9>, \QrrH
vjWgR9 4/{
public class FileSplitterFetch extends Thread { evk <<zi
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n,%^R
String sURL; //File URL dM.Ow!j
long nStartPos; //File Snippet Start Position ]= D
long nEndPos; //File Snippet End Position iv`-)UsE
int nThreadID; //Thread's ID T js{ )r9
boolean bDownOver = false; //Downing is over *hgsS~
boolean bStop = false; //Stop identical ~2;y4%K
FileAccessI fileAccessI = null; //File Access interface GDe$p;#"9g
LYKm2C*d
&G,v*5N8$K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $jL.TraV7
{ CA~S$H\"
this.sURL = sURL; !}m8]&
this.nStartPos = nStart; 5Z0x2jV
this.nEndPos = nEnd; x6P^IkL:
nThreadID = id; j}Mpc;XOc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cW>`Z:6{K
} TQfY%GKg(
2)H|/
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public void run() HM x9M$
{ 32J
while(nStartPos < nEndPos && !bStop) 3c"{Wu-}
{ VAz+J
!1]xKNp]
uu#+|ZD
try{ o W [-?
URL url = new URL(sURL); RR9s%>^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oOvbel`;
httpConnection.setRequestProperty("User-Agent","NetFox"); \8H"lcj:
String sProperty = "bytes="+nStartPos+"-"; oOw"k*,h:S
httpConnection.setRequestProperty("RANGE",sProperty); ^`9OA`2
Utility.log(sProperty); g M.(BN
iE{SqX
eLWzd_ln
InputStream input = httpConnection.getInputStream(); ![Y$[l
//logResponseHead(httpConnection); Yi,um-%
q\G@Nn^
-rrg?4
byte[] b = new byte[1024]; gNBI?xs`p
int nRead; EyiM`)!5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !ym5'h
{ =!2
nStartPos += fileAccessI.write(b,0,nRead); l$NEx0Dffz
//if(nThreadID == 1) x-EAu3=V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qyC"}y-
} $~l:l[Zs
ZGBcy}U(k
(["u"m%
Utility.log("Thread " + nThreadID + " is over!"); CK%W+";
bDownOver = true; :2+:(^l
//nPos = fileAccessI.write (b,0,nRead); Sx7xb]3XI"
} NH!!.Z"
catch(Exception e){e.printStackTrace ();} 'L7.a'
} @A%`\Ea%
} :>u{BG;=79
0Oq1ay^
[&&4lKC}u
//打印回应的头信息 ^ +G> N
public void logResponseHead(HttpURLConnection con) [VHt#JuN,
{ +yk>jx
for(int i=1;;i++) mD:!"h/
{ 4D5)<3N=d'
String header=con.getHeaderFieldKey(i); scmbDaOn
if(header!=null) S45jY=)z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v,! u{QP
Utility.log(header+" : "+con.getHeaderField(header)); +Y+kx"8
else K!j2AP3
break; n$8A"'.M
} 7>TG ]&
} }OZfsYPz}T
}T@AoIR0t
C\Rd]P8\
public void splitterStop() )Lq FZ~B
{ ZzY6M"eUXD
bStop = true; x1Uj4*Au
} sj1x>
8w4.|h5FP
9(Z)c
} QGa"HG5NF
-3C~}~$>`
<_}u5E)7(
/* _XN sDW4|
**FileAccess.java E;SFf
*//文件访问(定位，写) 3z#16*
package NetFox; QCMF_;aNI
import java.io.*; $t^`Pt*:u
'-et:Lv7
?V+=uTCq
public class FileAccessI implements Serializable{ _nF_RpS
on~rrSK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <?!#QA
RandomAccessFile oSavedFile; Xg"=,j2
long nPos; Gh.02
LY7'wONx
(_D#gr{S=
public FileAccessI() throws IOException |1EM )zh6
{ 5_PD?lg
this("",0); KpWQ;3D2
} g]S.u8K8m
DY%E&Vd:h
?%?@?W>s@
public FileAccessI(String sName,long nPos) throws IOException awUIYAgJ3
{ rd6?;K0
oSavedFile = new RandomAccessFile(sName,"rw"); 3OTSLF/
this.nPos = nPos; k&^fIz
oSavedFile.seek(nPos); %*,'&S
} k;]&`c^5
m$3&r2vgi
(RQ kwu/
public synchronized int write(byte[] b,int nStart,int nLen) [b`k\~N4r
{ \ /o`CV{O
int n = -1; NVQIRQ.
try{ r__uPyIMG/
oSavedFile.write(b,nStart,nLen); ?>e-6*.
n = nLen; lUDzfJ}3
} <)&;9C
catch(IOException e) 3K{'~?mM
{ Bb m1&d#
e.printStackTrace (); 3*ZE``
} n-uoY<;hp
\'shnzs
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return n; SH"O<cDp
} 4e* rBTl
mN,Od?q[
\S _ycn
} 2x0[@cTi?
zXB.)4T
3(X"IoNQ
/* lbMb
**SiteInfoBean.java 4]B(2FR[8
*/ XB2[{XH,
package NetFox; .(D-vkz'
=MA$xz3
P@)zNik[
public class SiteInfoBean { lO[[iMHl<
>%t"VpvR
R'He(x
private String sSiteURL; //Site's URL 5G|(od3
private String sFilePath; //Saved File's Path sdrALl;w|
private String sFileName; //Saved File's Name C/!kMMh>vV
private int nSplitter; //Count of Splited Downloading File |?g k%g
n"*A.
t ?rUbN
public SiteInfoBean() (k4>I"x)
{//nSplitter的缺省值为5 du Pzt
//default value of nSplitter is 5 U2seD5I
this("","","",5); xwq {0jY
} }}@xx&
id'E_]r
J#"@~Q+a`@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~0eJ6i
{ Zgd| J T7
sSiteURL= sURL; |4UW.dGHPo
sFilePath = sPath; #A+ dj| b
sFileName = sName; Y<odXFIS
this.nSplitter = nSpiltter; <7-3j{065
;.+sz(:hm
w,n&K6<
} R^4JM,v9x`
rZEL7{
3w6}%=)$8
public String getSSiteURL() :+06M@
{ VG'M=O{)3
return sSiteURL; DAa??/,x7
} ,t2Mur
ZjLuqo

public void setSSiteURL(String value) >UlAae44
{ :(ni/,~Q
sSiteURL = value; ^VabXGzo#
} vr/*z euA
N;gI %6
W!6&T [j>
public String getSFilePath() a*/%EP3
{ `3GYV|LeQ
return sFilePath; PaIE=Q4gJ
} l7vU{Fd-h^
J%r$jpd'
vf}.)
public void setSFilePath(String value) v@n0ma=
{ Y~,ZBl,
sFilePath = value; `?P)RS30
} ]fiAV|'^
BeFCt;
ey!QAEg"X1
public String getSFileName() 8p"R4
{ ,Kl6vw8Htg
return sFileName; +s$` kl
} <+3-(&
Cg#@JuwHa
MVDEVq0
public void setSFileName(String value) ;Gnk8lIsb
{ mssCnr;
sFileName = value; V;@kWE>3
} i`st'\I
&GKtD)
y*oH"]D
public int getNSplitter() OUM^u*
{ caH!(V}6
return nSplitter; {)KH%
} FV~ENpncP
:n0czO6E
.G/>X%X
public void setNSplitter(int nCount) e<Bwduy
{ jXH?os%
nSplitter = nCount; JbR;E`8
} P,RdYM06
} P&$ m2^K
Ul{{g$
F<9S,
/* Ew,1*WK!
**Utility.java L!qXt(`
*/ 4).i4]%LH
package NetFox; qvHRP@
f=,(0ygt/
n-)Xs;`2
public class Utility { N"k IQe*}1
I 7 B$X=
Rzj1D:?X@
public Utility() a9%^Jvm"
{ D-KQRe2@
vQ_D%f4;
JlMD_pA
} Ex`!C]sQ
:Sc"fG,g)
//线程睡眠 Ho!dtEs
public static void sleep(int nSecond) ]>T4\?aC
{ @!np 0#
try{ K.l7yBm
Thread.sleep(nSecond); Kh'7N!
} /&jh10}H
catch(Exception e) 40i]I@:JK
{ sgxD5xj}4
e.printStackTrace (); mh7JPbX|
} ]38{du
} E9]\ I>v
`{v!|.d<
//日志 A@81wv
public static void log(String sMsg) ;&$Nn'~a
{ d!z}! :
System.err.println(sMsg); kuI%0)iZn
} ^6kE tTO*
=F9!)r
}:zTz%_K
public static void log(int sMsg) a?K3/0G
{ ZOIx+%/Vd#
System.err.println(sMsg); O86[`,
} y(92Th$
} 81jVjf?`
.KeZZLH
i"Z
/* z7$,m#tw
**TestMethod.java c7R<5f
*/ ?P>3~3 B
package NetFox; eY'< UO
u301xc,N<z
@SX-=Nr
public class TestMethod { Mv%"aFC
E/5/5'gBJO
VxTrL}{(6
public TestMethod() z-g"`w:Lj
{ ///xx/weblogic60b2_win.exe (;6vT'hE
try{ $AyE6j_1gX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b>]MZhLJe
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Nfo`Q0\[P
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8Ts_;uId
fileFetch.start(); g*-%.fNA
} XtP5IN\S
catch(Exception e){e.printStackTrace ();} 8nKb mjM
ekV|a1)
X1Vj"4'wT
} P+2@,?9#
Mq,2S
57~/QEdy
public static void main(String[] args) 'OjsV$_
{ )wdTs>W7
new TestMethod(); o>Faq+@
} s"-gnW
} mLb>*xt$b@
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