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)); [-bT_X
} vKX $Nf
for(int i=0;i<nEndPos.length-1;i++) wPl!}HNf
{ o5N];Nj
nEndPos = nStartPos[i+1]; M!s@w%0?'
} \q8D7/q
nEndPos[nEndPos.length-1] = nFileLength; =lf&mD _/
} Hkv4t5F
} U*' YGv
L|3wGY9E
t: =
//启动子线程 "lp),
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fi[c^e+IX
for(int i=0;i<nStartPos.length;i++) O_p:`h:;M
{ oR=^NEJv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ass8c]H@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <Dr*^GX>?
nStartPos,nEndPos,i); ,cvLvN8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gJyFt8Z<
fileSplitterFetch.start(); QPH2TXw
} M-2:$;D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "$Wi SR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <9S?wju4W'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", KJwkkCE/=
nEndPos = " + nFileLength); I]`>m3SJ
// fileSplitterFetch[nPos.length-1].start(); ~[i,f0O,
z:aT5D
COw]1R
//等待子线程结束 9GdrJ~h
//int count = 0; S!GjCog^J
//是否结束while循环 'U)|m
boolean breakWhile = false; #pxc6W /
+|OkT
Bu'PDy~W,
while(!bStop) / 4K*iq
{ EX[X|"r
write_nPos(); j/bebR}X
Utility.sleep(500); sBuVm<H
breakWhile = true; g#V3u=I8~
d0b--v/
2O|o%`?
for(int i=0;i<nStartPos.length;i++) $ ;/Ny)"
{ G6zFCgFJ^y
if(!fileSplitterFetch.bDownOver) gz[Ng> D+
{ V 'Gi2gNaP
breakWhile = false; @NXGVmY1}
break; qVFz-!6b
} Q^v8n1
} <G59>H5
if(breakWhile) a$MMp=p
break; ^c1I'9(r5
s &v<5W2P
>qn@E?Uf
//count++; }TRr*] P<%
//if(count>4) W|T"'M_
// siteStop(); .ukP)rGe
} H{x}gBQ
unmuY^+<
n>\BPiz
System.err.println("文件下载结束！"); `}F=Zjy
} twx8TQ9
catch(Exception e){e.printStackTrace ();} ij6ME6
} c7IgndVAV
jow^~
\PzC:H
//获得文件长度 &_&])V)<\S
public long getFileSize() `X]-blHo
{ F'Fc)9qFa<
int nFileLength = -1; WjGv%^?
try{ J%xp1/=2
URL url = new URL(siteInfoBean.getSSiteURL()); .9WUp>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M6!kn~
httpConnection.setRequestProperty("User-Agent","NetFox"); ~aH*ZA*f
5/mW:G,&
"HVwm>qEi
int responseCode=httpConnection.getResponseCode(); B[-%A!3 F
if(responseCode>=400) Z>a_vC
{ d {moU\W
processErrorCode(responseCode); kT UQ8U
return -2; //-2 represent access is error 9U58#
} /U)w:B+p/g
K4xZT+Qb
%yQ-~T@
String sHeader; *ZGQ`#1.X6
mCtuyGY
)xP]rOT
for(int i=1;;i++) ~@z5Ld3xz
{ @P"q`*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )G ,LG0"-
//Utility.log(in.readLine()); Z8kO*LYv
sHeader=httpConnection.getHeaderFieldKey(i); QA.B.U7!
if(sHeader!=null) <V"'j
{ .F)b9d[?
if(sHeader.equals("Content-Length")) '[5tc fG#z
{ F& H~JJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h|%d=`P,
break; %M9^QHyo@
} [}lv!KmzW
} n=t%,[Op
else *NDLGdQqz
break; v{=-#9-4 &
} Q%QpG)E
} X!,Ngmw.
catch(IOException e){e.printStackTrace ();} -H.;73Kb[
catch(Exception e){e.printStackTrace ();} #>~$`Sg
h&yaug,.
Y*f7& '[
Utility.log(nFileLength); >K-O2dry*
c.&vWmLSGE
jRB:o?S
return nFileLength; cY#TH|M
} zv#i\8h^p
3 %dbfT j
d&?B/E^
//保存下载信息（文件指针位置） /Rk5n
private void write_nPos() 3Luv$6
{ :":W(O
try{ OU9=O>
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0+r/>-3]
output.writeInt(nStartPos.length); 4_t aCK
for(int i=0;i<nStartPos.length;i++) Z/;rM8[{&
{ wC=IN
// output.writeLong(nPos); K N0S$nW+
output.writeLong(fileSplitterFetch.nStartPos); ;=)CjC8)
output.writeLong(fileSplitterFetch.nEndPos); xvp{F9~qT
} #JuO
output.close(); 'L3 \I
} &r DOqj
catch(IOException e){e.printStackTrace ();} 66)@4 3V
catch(Exception e){e.printStackTrace ();} _BtlO(0&
} ,[Cl'B
[b;Oalw
Ylt[Ks<2
//读取保存的下载信息（文件指针位置） %F&j B
private void read_nPos() g:;v]
{ S3qUzK
try{ g"C$B Fc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r7ywK9UL
int nCount = input.readInt(); tk}qvW.Ii
nStartPos = new long[nCount]; ,*S?L qv^
nEndPos = new long[nCount]; \~y>aYy
for(int i=0;i<nStartPos.length;i++) -zc9=n<5
{ z^}T= $&
nStartPos = input.readLong(); #|$i H kVY
nEndPos = input.readLong(); yo (&~r
} |[o2S90
input.close(); r*+9<8-ZX<
} &% M^:WT
catch(IOException e){e.printStackTrace ();} 0U`Ic_.
catch(Exception e){e.printStackTrace ();} Jz%&-e3
} :?RK>}4|F
S~Q7>oNm
Z/beROW)
private void processErrorCode(int nErrorCode) =/dW5qy;*+
{ sSD(mO<(
System.err.println("Error Code : " + nErrorCode); IUc!nxF#
} 3\mFK$#sr
i,4JS,82I
7BI0g@$Nn]
//停止文件下载 R>gj"nB
public void siteStop() y-sQ"HPN
{ yuI5# VUS
bStop = true; E/s3@-/
for(int i=0;i<nStartPos.length;i++) &nz1[,
fileSplitterFetch.splitterStop(); f+I*aBQ
X:62)^~'
8<.KWr
} wau81rSd
} 79x^zqLb
//负责部分文件的抓取 *^.b}K%
**FileSplitterFetch.java -BoN}xE4
*/ I}k!i+Yl
package NetFox; &|{K*pNa
6f1;4Jfp
*ZaK+ B
import java.io.*; g_n=vO('X
import java.net.*; OvK_CN{
C|!E'8Rw
>Q+EqT
public class FileSplitterFetch extends Thread { |qbJ]v!
k+i}U9c"
NqF-[G<
String sURL; //File URL mup3ua]!
long nStartPos; //File Snippet Start Position h{PLyWH
long nEndPos; //File Snippet End Position ojIh;e
int nThreadID; //Thread's ID 4&|9304<H
boolean bDownOver = false; //Downing is over "lmiGR*u
boolean bStop = false; //Stop identical 5utj$ha2
FileAccessI fileAccessI = null; //File Access interface gWWy!H
z6{0\#'K
v"$; aJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &kO4^ A
{ Xq)'p8C?
this.sURL = sURL; >nr1|2
this.nStartPos = nStart; {g )kT_
this.nEndPos = nEnd; Vq<|DM3z<
nThreadID = id; 0q`'65 lx
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2RE }l=h5
} le[5a=e(
t}oxHEa V
eq4<
public void run() e|4jT7L}
{ y|lP.N/
while(nStartPos < nEndPos && !bStop) UoKBcarm
{ vNtbb]')m
+ZZiZ&y
ZcdS?Z2k
try{ 3G>E>yJ
URL url = new URL(sURL); ?tSY=DK\n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;w6\r!O,
httpConnection.setRequestProperty("User-Agent","NetFox"); u YH{4%
String sProperty = "bytes="+nStartPos+"-"; $x2<D :
httpConnection.setRequestProperty("RANGE",sProperty); vF([mOZ
Utility.log(sProperty); 0cS.|\ZTA
`$#64UZ>U1
-#Wc@\;
InputStream input = httpConnection.getInputStream(); K1+,y1c
//logResponseHead(httpConnection); m=}kGzIY4
@wa/p`gj5w
km|~DkJ\a`
byte[] b = new byte[1024]; NKI&n]EO
int nRead; c2F`S1Nu<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) P)}:lTe
{ mGY74>/
nStartPos += fileAccessI.write(b,0,nRead); { aB_t%`w
//if(nThreadID == 1) (sl]%RjGa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iu1iO;q
} _*`AGda
Y5npz^i
m[8#h(s*t
Utility.log("Thread " + nThreadID + " is over!"); -u9{R\S
bDownOver = true; @\q~OyV
//nPos = fileAccessI.write (b,0,nRead); <]!IC]+
} 8vP d~te
catch(Exception e){e.printStackTrace ();} Aw|3W ]
} '$U"RP^(
} <Jvrmm[
j5HOdy2
dm 2_Fj
//打印回应的头信息 Q,DumOq
public void logResponseHead(HttpURLConnection con) t)v#y!Ci"
{ sP&E{{<QTF
for(int i=1;;i++) 4^i*1&"
{ P.fgt>v]
String header=con.getHeaderFieldKey(i); f~U|flL^
if(header!=null) ~O|0.)71]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gT+/CVj R
Utility.log(header+" : "+con.getHeaderField(header)); Mz{>vb
else My1E@<
break; ahf$#UQLb
} @a3<fmJ
} *Js<VR
:g\qj? o
d6n6= [*
public void splitterStop() |0bSxPXn!
{ xGH%4J\
bStop = true; 3NJH"amk
} :@3d
onmO>q*
vLC&C-f
} zzx4;C",u
[NFAdE
~/.&Z`ls
/* 0FW=8hFp,
**FileAccess.java ~KNxAxyVi
*//文件访问(定位，写) 3&zmy'b*:
package NetFox; f2Slsl;
import java.io.*; C[Fh^
zZ wD)p?_g
3 (<!pA
public class FileAccessI implements Serializable{ \:#b9t{B-
8<G@s`*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v0y7N_U5n
RandomAccessFile oSavedFile; {B}0LJIpL
long nPos; Ay_<?F+&
Gm%[@7-
K0#tg^z5d
public FileAccessI() throws IOException 0I&rZMpF&
{ ht-6_]+ME
this("",0); kOjq LA
} qI"mW@G~H
&0lNj@/
kP6r=HH@
public FileAccessI(String sName,long nPos) throws IOException l&yR-FJ7KY
{ <)&ykcB
oSavedFile = new RandomAccessFile(sName,"rw"); JxWHrsh[
this.nPos = nPos; bH.">IV
oSavedFile.seek(nPos); 4EELaP|%
} HWd,1
D"Xm9 (
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public synchronized int write(byte[] b,int nStart,int nLen) p\HXE4d'
{ 2<O hO ^
int n = -1; 1ERz:\
try{ jgYiuM3c\
oSavedFile.write(b,nStart,nLen); $@NZ*m%?JQ
n = nLen; N7;2BUIXJ
} M-Js"cB[
catch(IOException e) Pf!K()<uJ
{ 4VooU [Ka(
e.printStackTrace (); FD6|>G
} x=Ru@nK;
1TVTP2&Rd
BAPi<U'D
return n; "-Ns1A8
} J>'o,"D
hb_Ia]b
RWoiV10
} x O)nS _I
7}#vANm
78Gvc~j
/* %iGME%oXr
**SiteInfoBean.java e9:l
*/ $`Ou*
package NetFox; {L+?n*;CA
l(`w]=t&
bT;C8i4b\H
public class SiteInfoBean { g&za/F
;aF / <r
:{fsfZXXr
private String sSiteURL; //Site's URL q4Z\y
private String sFilePath; //Saved File's Path J3'"-,Hv
private String sFileName; //Saved File's Name QVP $e`4
private int nSplitter; //Count of Splited Downloading File CeZ5Ti?F
QA%GK4F70
|9Y9pked8
public SiteInfoBean() 0Icyi#N
{//nSplitter的缺省值为5 >Kr,(8rA
//default value of nSplitter is 5 z(m*]kpL"
this("","","",5); vSX 6~m
} D"o>\Q
]EK"AuEz`
mrJQB I+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o1Xk\R{
{ m$o|s1t
sSiteURL= sURL; hsl8@=_ B
sFilePath = sPath; _ 9k^Hd[L$
sFileName = sName; W$3p,VTMmB
this.nSplitter = nSpiltter; ?T^$,1-
1"'//0 7
$v^F>*I1
} "qF&%&#r'
[$./'-I]
@wg*~"d
public String getSSiteURL() Y,8M[UIK
{ $HH(8NoL
return sSiteURL; *s!8BwiE
} _ x7Vyy5
:4WwCpgz,
Y3-P*
public void setSSiteURL(String value) Hp,r @
{ 2M;{|U
sSiteURL = value; mr/^lnO
} 1xx-}AIH#
T.{I~_
tVe*J@i\$
public String getSFilePath() ,:#prT[P"
{ K.cNx
return sFilePath; <1@_MYo
} GJW1|Fk
E:i3 /Ep?
KctD=6
public void setSFilePath(String value) ^C'k.pV n~
{ 4Q]+tXes
sFilePath = value; "_(o% \"7
} kL&^/([9
v/^2K,[0>
y/PEm)=Tt
public String getSFileName() n3)g{K^
{ ~U^0z|.
return sFileName; #v v k7
} -_2=NA?t
4];NX
h)YqC$A-s
public void setSFileName(String value) q<7Nz]Td
{ yx-{}Yj^
sFileName = value; LAr6J
} YY.;J3C
2=#O4k.@
`R; ct4-
public int getNSplitter() {g);HnmPN
{ :H?p^d e
return nSplitter; p?!]sO1l
} r3KV.##u,
*mBEF"
51rM6 BT
public void setNSplitter(int nCount) NfN#q:w1
{ $GYy[-.`
nSplitter = nCount; ]];7ozS)X
} ]{y ';MZ
} C4n5U^
!|`YNsR
=GLsoc-b
/* @P~u k
**Utility.java S>'wb{jj!
*/ qV(Plt%
package NetFox; 3rWqt
-m__I U
}XAoMp
public class Utility { )`U T#5
pZWp2hj{X
.AV--oA~
public Utility() Tn-H8;Hg
{ 3FS:]|oC
ha(hG3C
HFf| >&c&
} ]])i"oew
HDC`g
//线程睡眠 )kdPAw
public static void sleep(int nSecond) b|xz`wUH0$
{ >`lf1x
try{ ?49wq4L;a
Thread.sleep(nSecond); PS6G 7
} 1&m08dZm5
catch(Exception e) {)Gh~~57_W
{ [,fMh $t
e.printStackTrace (); PPmZ[N9(;
} !>! l=Z
} QALMF rWH
pM4 j=F
//日志 "PuP J|
public static void log(String sMsg) .2u%;)S
{ yJgnw6>r2
System.err.println(sMsg); zZA I"\;W
} I]} MK?
7-(tTBH
(apAUIE
public static void log(int sMsg) $YW z~^f
{ jCy2bE
System.err.println(sMsg); %5uuB4P&|$
} =b;v:HC
} c[Y7tj%y
O[-wm;_(=*
ZL@7Mr!e
/* )ll}hGS
**TestMethod.java MEo+S
*/ Ib!`ChZ
package NetFox; !.F`8OD`u
) .#,1
(I\aGGW
public class TestMethod { fPspJug
C~:aol i;
{)`5*sd
public TestMethod() &hZcjdB
{ ///xx/weblogic60b2_win.exe =n$,Vv4A
try{ 6KV&E8Gn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (?~F}u v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |>p\*Dl}H
SiteFileFetch fileFetch = new SiteFileFetch(bean); g\n@(T$)
fileFetch.start(); 9}5Q5OZ
} vL-%"*>v
catch(Exception e){e.printStackTrace ();} jd~r~.y
f9#B(4Tgi
BPC$ v\a
} g*8sh
)L^WD$"'Q
:egSW2"5S
public static void main(String[] args) whvM^
{ `oq 3G }
new TestMethod(); /(vT49(]
} x!Wl&
} 5vY1 XZt{
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