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)); -9(pOwN |m
} kbZpi`w
for(int i=0;i<nEndPos.length-1;i++) .Ky)Co
{ I %|;M%B
nEndPos = nStartPos[i+1]; in`|.#
} bL/DjsZ@
nEndPos[nEndPos.length-1] = nFileLength; &1ZUMc
} oqbhb1D1<
} @S1Z"%S
Ty}Y/jW
@;}vK=6L
//启动子线程 HYl~)O>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4`Lr^q}M+
for(int i=0;i<nStartPos.length;i++) _fS4a134R
{ 2])e}&i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Sm;@MI<@/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `N8t2yF
nStartPos,nEndPos,i); }VeE4-p B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c&C*'c-r
fileSplitterFetch.start(); z0@BBXQ`
} ox5WboL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V&7NN=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q hdG(`PY~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", izs=5
nEndPos = " + nFileLength); ojc.ykP$
// fileSplitterFetch[nPos.length-1].start(); YP>J'{?b*"
DMlr%)@{
Vllxv6/_
//等待子线程结束 Zxh<pd25Y
//int count = 0; p}8?#5`/w
//是否结束while循环 3Uej]}c
boolean breakWhile = false; _{$<s[S
!6,rN_a@Y
v[V7$.%5Q
while(!bStop) X.ecA`0
{ [,(+r7aB
write_nPos(); n;wViw
Utility.sleep(500); Q" r y@ (I
breakWhile = true; wHh6y?g\
8Oz9 UcG
{.ypZ8JU
for(int i=0;i<nStartPos.length;i++) #4<=Ira5
{ 6-FM<@H{
if(!fileSplitterFetch.bDownOver) RK=Pm7L:`y
{ S0M i
breakWhile = false; 0#4A0[vV
break; z_Hkw3?
} &OA6Zw/A
} 3)I]bui
if(breakWhile) q1v7(`O
break; 29cx(
*HB 32 =qD
ZG-#YF.1
//count++; GL~ Wnt
//if(count>4) -fp/3-
// siteStop(); 5)A[NTNJx
} .5);W;`X
cg_ " }]Y1
d"L(eI}G
System.err.println("文件下载结束！"); (4?^X
} e=3C*+lq\
catch(Exception e){e.printStackTrace ();} ?d+ri
} X ]W)D S
hV:++g
"!CVm{7[
//获得文件长度 p=3t!3
public long getFileSize() HJBGxyw
{ {Qc,Nl [?
int nFileLength = -1; xojt s;n
try{ Uz~B`
URL url = new URL(siteInfoBean.getSSiteURL()); Kwi+}B!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UA4c4~$S
httpConnection.setRequestProperty("User-Agent","NetFox"); @ qi|}($
w 62m}5eA
[XttT
int responseCode=httpConnection.getResponseCode(); 8!YQ9T[
if(responseCode>=400) 'n=bQ"bQu
{ yEk|(6+^
processErrorCode(responseCode); =CO) Q2
return -2; //-2 represent access is error vG7Mk8mIr
} l(Dr@LB~
TQb@szp:|
rIb~@cR)
String sHeader; )Ly~\*
u80C>sQ
&*Xrh7K2e
for(int i=1;;i++) d2d8,Vg
{ &n6L;y-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dm]g:KWg
//Utility.log(in.readLine()); RN|Bk
sHeader=httpConnection.getHeaderFieldKey(i); u})*6l.
if(sHeader!=null) 7r^Cs#b+I
{ (>E/C^Tc%
if(sHeader.equals("Content-Length")) #d*0 )w
{ ({@"{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5D2mZ/
break; q*5L",
} DBG0)=SHy
} LT>_Y`5>
else hW'b'x<
break; ''D7Bat@
} ."gq[0_YS
} 4f~sRubK
catch(IOException e){e.printStackTrace ();} DaJ,(DJY
catch(Exception e){e.printStackTrace ();} wEwRW
*C0a,G4
8EMBqhl
Utility.log(nFileLength); cvo+{u$s
dNY'uv&Y
Thu_`QP^
return nFileLength; ~5h4 Gy)
} $MGKGWx@E
q'a]DJ`
U;TS7A3
//保存下载信息（文件指针位置） |vm-(HY!
private void write_nPos() SvQ|SKE':
{ SjpCf8Z(
try{ *aC[Tv[-P
output = new DataOutputStream(new FileOutputStream(tmpFile)); [s`B0V`04
output.writeInt(nStartPos.length); [[]yQ "
for(int i=0;i<nStartPos.length;i++) -G@uB_Cs
{ he/rt#
// output.writeLong(nPos); G[]%1 _QCO
output.writeLong(fileSplitterFetch.nStartPos); r]&sXKDc
output.writeLong(fileSplitterFetch.nEndPos); V=p"1!(
} -s!J3DB
output.close(); TB?'<hD:
} 0Ze&GK'Hf
catch(IOException e){e.printStackTrace ();} .>}I/+n
catch(Exception e){e.printStackTrace ();} R9^vAS4t[O
} H\n6t-l
DTuco9yr[
H ?9Bo!
//读取保存的下载信息（文件指针位置） ;dMr2y`6
private void read_nPos() jA;b2A]G
{ W1<*9O
try{ ^|6#Vx
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); YpXd5;'
int nCount = input.readInt(); `GBJa k
nStartPos = new long[nCount]; ,jeHL@>w[
nEndPos = new long[nCount]; 74:( -vS
for(int i=0;i<nStartPos.length;i++) Te~jYkCd
{ <}A6 )=T
nStartPos = input.readLong(); N\&VJc
nEndPos = input.readLong(); 2;*G!rE&*`
} 0tL5t7/Gr
input.close(); ks("( nU
} wJJ|]^0.
catch(IOException e){e.printStackTrace ();} =liyd74%`
catch(Exception e){e.printStackTrace ();} /m;Bwu
} A^+kA)8
h*D -Vo
v;G/8>GRy
private void processErrorCode(int nErrorCode) u/wX7s
{ W`JI/
System.err.println("Error Code : " + nErrorCode); 1 oKY7i$
} &&52ji<3
iG"v
.sQV0jF{
//停止文件下载 !`7evV:
public void siteStop() x1`(Z|RJ
{ o6|- :u5_/
bStop = true; lH`c&LL-=!
for(int i=0;i<nStartPos.length;i++) l{.PyU5)
fileSplitterFetch.splitterStop(); *0@Z+'M?
jg'"?KSU~
D4(73
} frm[<-~w0
} LgX2KU"
//负责部分文件的抓取 8YE4ln
**FileSplitterFetch.java YU0pWM
*/ ^`dMjeF
package NetFox; 4clCZ@\K^
)'g4Ty
J Q*~le*
import java.io.*; !Sy9v
import java.net.*; ".Q]FE@>
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0Bp0ScE|FA
public class FileSplitterFetch extends Thread { \24'iYtqW
}id)~h_@
,wg(}y'
String sURL; //File URL .Jg<H %%f
long nStartPos; //File Snippet Start Position n#WOIweInf
long nEndPos; //File Snippet End Position {wt9/IlG1
int nThreadID; //Thread's ID N4-Y0BO
boolean bDownOver = false; //Downing is over .Wp(@l'Hd
boolean bStop = false; //Stop identical dc~vQDNw[X
FileAccessI fileAccessI = null; //File Access interface K%BFR,)g
^/Yk*Ny
:N^B54o%6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -{JReplc
{ K iXD1Zpz
this.sURL = sURL; _C1u}1hW#
this.nStartPos = nStart; ]Hi1^Y<
this.nEndPos = nEnd; qFDy)4H)
nThreadID = id; #')]~Xa
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U v>^ Z2
} tRc3<>
J32{#\By
`WC4:8
public void run() ZJGIib
{ S\sy^Kt~4:
while(nStartPos < nEndPos && !bStop) -gC%*S5&
{ ho~WD'i
H3d|eO4+W
K)`R?CZ:s
try{ x~8R.Sg
URL url = new URL(sURL); <?8cVLW}O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d/3&3>/
httpConnection.setRequestProperty("User-Agent","NetFox"); wod{C!
String sProperty = "bytes="+nStartPos+"-"; ~ W8 M3(^
httpConnection.setRequestProperty("RANGE",sProperty); r z@%rOWV
Utility.log(sProperty); v[x 5@$
Qd% (]L[N.
cw~GH
InputStream input = httpConnection.getInputStream(); l,A\]QDvl
//logResponseHead(httpConnection); hhylsm
=8p[ (<F=
"Ya;&F.'
byte[] b = new byte[1024]; F/A)2 H_
int nRead; CnY dj~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4U)%JK.ta
{ n Zx^ej\
nStartPos += fileAccessI.write(b,0,nRead); T?u*ey~Tv
//if(nThreadID == 1) /Z#AHfKF
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {BAZ`I
} Of-gG~
ci(BPnQ
-ECnX/ "
Utility.log("Thread " + nThreadID + " is over!"); 98<^!mwF
bDownOver = true; WwSyw?T
//nPos = fileAccessI.write (b,0,nRead); @.`HvS
} hdM?Uoo(4a
catch(Exception e){e.printStackTrace ();} *x2u
} Pj8Vl)8~NV
} }gX4dv B
Z,XivU&
FEa%wS{
//打印回应的头信息 Mwj7*pxUh
public void logResponseHead(HttpURLConnection con) {Y]3t9!\
{ N;m62N
for(int i=1;;i++) p<@+0Uw2
{ GBd mT-7
String header=con.getHeaderFieldKey(i); &w%%^ +n |
if(header!=null) Pm24;'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); J(XK%e[8
Utility.log(header+" : "+con.getHeaderField(header)); (@\0P H0
else zCwb>v
break; F>@z&a}(
} d+eb![fi
} 4HXNu,T'
W"xRf0\V
2V+[:>F
public void splitterStop() g@>y`AFnr
{ %-!:$ 1;
bStop = true; /h&>tYVio
} _@|_`5W
OW> >6zM
iqXsDgkr
} tjm@+xs
Rg~[X5
\nVoBW(
/* 5M3)7
**FileAccess.java zfml^N
*//文件访问(定位，写) gp{P _
package NetFox; etP`q:6^c
import java.io.*; FFF7f5F
$:DhK
k1FG$1.
public class FileAccessI implements Serializable{ P(zquKm
B"RZpx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 iF+50d
RandomAccessFile oSavedFile; 1 7hXg"B
long nPos; 0L7^Vr)
E|B1h!!\c
'BEM:1)
public FileAccessI() throws IOException YjG:ECj}
{ T=cb:PD{%
this("",0); nQ'AB~ Do
} Dw2$#d
&\r_g!Mh
EmcwX4|
public FileAccessI(String sName,long nPos) throws IOException iJu$&u
{ UDa\*
oSavedFile = new RandomAccessFile(sName,"rw"); @L^30>?l
this.nPos = nPos; 'cbD;+YH
oSavedFile.seek(nPos); 9n".Q-V;k
} ;|K(6)
Aa%ks+1
|G-o&m"
public synchronized int write(byte[] b,int nStart,int nLen) 'P-FeN^
{ RK=YFE 0
int n = -1; W&a<Q)o*I
try{ {D&:^f
oSavedFile.write(b,nStart,nLen); K:sC6|wG
n = nLen; <.6$zcW
} 9hs7B!3pc>
catch(IOException e) !1?Nc}T0Q&
{ * @j#13.
e.printStackTrace (); nr{}yQu
} gCS%J40r
F(:]lM|
3gmu-tv
return n; ps?B;P
} .gHL(*1P
;0\
j2{ '!
} %OsV(7
BhJ~jV"
<^jW
/* o#&;,9
**SiteInfoBean.java ^)/oDyO
*/ 30/(
package NetFox; s|&2QG0'7
mh`VZQ@
Q1@V?`rkS{
public class SiteInfoBean { #9Dixsl*Q
}vdhk0
=u`^QE
private String sSiteURL; //Site's URL rru `%~'O
private String sFilePath; //Saved File's Path Nb;Yti@Y.
private String sFileName; //Saved File's Name 1Q$Z'E}SK@
private int nSplitter; //Count of Splited Downloading File ;zvg] %
;H8A"$%n~
Ow]c,F}^
public SiteInfoBean() e c`3Qw
{//nSplitter的缺省值为5 G@QZmuj&KH
//default value of nSplitter is 5 <)(STo
this("","","",5); xlaBOKa%
} wXsA-H/`
tpi63<N
"n@=.x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) jW+L0RkX
{ mYzq[p_|j
sSiteURL= sURL; j^~WAWbFh
sFilePath = sPath; %@jv\J
sFileName = sName; SQbnn"
this.nSplitter = nSpiltter; yN~: 3
Jk7[}Jc$
vg1p{^N!
} wBXgzd%L
KArnNmJ9
K]q OLtc
public String getSSiteURL() }3!.e
{ ;dYpdy
return sSiteURL; p68) 0
} b-+iL
`+QrgtcEy4
q-}J0vu\K
public void setSSiteURL(String value) hQgi--Msw'
{ pOip$Z
sSiteURL = value; 8P'>%G<m
} Piz/vH6M}
d+fig{<b
_>*$%R
public String getSFilePath() A_@#V)D2
{ LE!3'^Zq
return sFilePath; E-irB/0
} @hWt.qO3s
{j E}mzi
Y0U<l1(|
public void setSFilePath(String value) ^YKEc0"w(
{ kf$0}T`
sFilePath = value; *,o)`
} J%_ :A"
]#[R^t
6?ylSQ]1
public String getSFileName() OY6lt.t
{ *Oo2rk nQ
return sFileName; C=AX{sn
} [N925?--S
Y]nY.5irL
e2%Y8ZJG.
public void setSFileName(String value) 4>>d "<}C
{ >kK
sFileName = value; e ?H`p"l
} w.Ft-RXA W
6P!M+PO
mg*[,_3q33
public int getNSplitter() z.pP~he
{ W04-D
return nSplitter; t*^Q`V wQ
} +B%ZB9
nYMdYt04sl
eEQ 4L\d
public void setNSplitter(int nCount) 3m?3I2k
{ )}7rM6hv
nSplitter = nCount; }S$]MY,*
} !B(6
} QE$sXP7&u
y%\kgWV
HkEfBQmh
/* Qg9 N?e{z
**Utility.java }0|,*BkI m
*/ KyNv)=x4c
package NetFox; o|AV2FM)
b4s.`%U
Z@ *^4Ve
public class Utility { B9n$8QS
IiIF4 pQ,
F\Ex$:%~
public Utility() aDTNr/I
{ 3xh~xE
d?*=<w!A
\:\rkc9LI
} M"#xjP.
9dr\=e6) C
//线程睡眠 z'MOuz~Y
public static void sleep(int nSecond) u:3~Ius
{ zVYX#- nv
try{ sC48o'8(
Thread.sleep(nSecond); [L"(flY(E
} SI)u@3hl&w
catch(Exception e) HkD6aJ:kA!
{ }i./,
e.printStackTrace (); NI\jGR.
} ,D3?N2mB
} mHUQtGAVQ
Pp6(7j
//日志 %<DXM`Y
public static void log(String sMsg) vu;pILN
{ -S OP8G
System.err.println(sMsg); hkee,PiiP
} } O8|_d
[ K;3Qf)
lh&Q{t(+8
public static void log(int sMsg) J"L+`i
{ e-ILUzT
System.err.println(sMsg); (u+3{Eb
} 5vxJ|Hse@
} &[}bHX/
YgCJ s;
0$%:zHi5g
/* dQQh$*IL?{
**TestMethod.java (2Z-NVU#
*/ VlXUrJ9&
package NetFox; n:,At]ky
R~iJ5@[
x-,+skZs
public class TestMethod { U@!e&QPn
F??})YX
o nt8q8
public TestMethod() D$+9`
{ ///xx/weblogic60b2_win.exe T$)&8"Xya
try{ +6-c<m|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Fx*iAH\e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K2<"O qp_W
SiteFileFetch fileFetch = new SiteFileFetch(bean); j{U?kW{o
fileFetch.start(); 9`81br+~
} R$IxR=hMx
catch(Exception e){e.printStackTrace ();} j BS$xW
Q\z6/1:9Z
fwK5p?Xhm
} ~oy=2Q<Z
d`q<!qFZh
`h}fS4CO
public static void main(String[] args) 9q5jqFQ
{ X]d;x/2
new TestMethod(); A}v!vVg
} L\)ssOuh
} )-%3;e<w
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