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)); !D|c2
} 6]NaP_\0
for(int i=0;i<nEndPos.length-1;i++) rd1EA|T
{ 3-v&ktD&N'
nEndPos = nStartPos[i+1]; L}=t"y
} 6`WI S4
nEndPos[nEndPos.length-1] = nFileLength; '_B;e=v`
} >qS2ha
} Plj>+XRO
Fk`|?pQm
a3J' c
//启动子线程 Nh[H[1"J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; C Ef*:kr
for(int i=0;i<nStartPos.length;i++) D%~"]WnZ\Q
{ MGLcM&oR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rH$M6S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @~&1!
nStartPos,nEndPos,i); ~?zu5,vb
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Aaug0X
fileSplitterFetch.start(); S{jm4LZ
} i6P'_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .2V?G]u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?h)T\z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", WP5Vev9*+
nEndPos = " + nFileLength); !:c_i,N
// fileSplitterFetch[nPos.length-1].start(); >udu~
F/ui(4
.L9n
//等待子线程结束 ]]9VI0
//int count = 0; W4q |55
//是否结束while循环 QB"+B]rV
boolean breakWhile = false; Ij2Th]
a"m-&mN
3?Fe(!@
while(!bStop) -unQ4G
{ %m##i
write_nPos(); cJ#n<Rsz
Utility.sleep(500); *r)dtI*
breakWhile = true; I{i6e'.jP
E<'V6T9bi
5}TTf2&Xo#
for(int i=0;i<nStartPos.length;i++) .^8rO,H[
{ c)Ne/E{!0
if(!fileSplitterFetch.bDownOver) s\e b
{ ?tkl cYB
breakWhile = false; a7sX*5t{R
break; yG2rAG_G&
} xbzO'C
} wufQyT`
if(breakWhile) n(#[[k9&Ic
break; qOflvf
4+:'$Nw
vG:S(/\>
//count++; Kf#iF*
//if(count>4) {7Hc00FM
// siteStop(); D*'sOB(
} P6A##z
hE7rnn{
0:$pJtx"
System.err.println("文件下载结束！"); $!^C|,CS
} ko"xR%Q
catch(Exception e){e.printStackTrace ();} &q +l5L"
} "gt1pf~y
{E.A?yej9
vCUbbQz
//获得文件长度 K%UjPzPWw
public long getFileSize() o|w w>m
{ y"k%Wa`*
int nFileLength = -1; K/_"ybR7
try{ _<'?s>(U'
URL url = new URL(siteInfoBean.getSSiteURL()); >z73uKA(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X6=o vm
httpConnection.setRequestProperty("User-Agent","NetFox"); 6?a z
r}}2Kl
P 1
int responseCode=httpConnection.getResponseCode(); JAy-N bb\
if(responseCode>=400) tT+W>oA/M
{ #e1iYFgS
processErrorCode(responseCode); |uI~}pSG
return -2; //-2 represent access is error `VF_rC[?
} _jH./ @G
jhJ<JDJ?`
FiSx"o
String sHeader; mY]o_\`
7~);,#[ky
#Jt1AV
for(int i=1;;i++) sRZ?Ilua6
{ ([#'G+MC&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G @EEh.s9
//Utility.log(in.readLine()); ">MsV/
sHeader=httpConnection.getHeaderFieldKey(i); P9 y+rF.
if(sHeader!=null) Dl,sl>{
{ lMcO2006L
if(sHeader.equals("Content-Length")) V+r&Z<&
{ )l.AsfW%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {R"mvB`
break; f:6F5G
} FjMKb
} F6}YM|
else q>wO=qWx
break; h!Y##_&&4
} F'CJN$6Mw/
} Wf-XH|j[
catch(IOException e){e.printStackTrace ();} KK{_s=t%<
catch(Exception e){e.printStackTrace ();} )2#qi/
A8-a}0Gh
X&i;WI
Utility.log(nFileLength); 6:AEg
fs-LaV 0
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return nFileLength; ";7/8(LBZ
} 3177R>0
;-BN~1Jg
$$EEhy
//保存下载信息（文件指针位置） 1OqVV?oz
private void write_nPos() KW3<5+w]c
{ <L<^uFB
try{ O#p_rfQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9XKqsvdS
output.writeInt(nStartPos.length); Ep:hObWG)
for(int i=0;i<nStartPos.length;i++) %I{>H%CjE
{ 6J@,bB jVz
// output.writeLong(nPos); C%{2 sMJz
output.writeLong(fileSplitterFetch.nStartPos); 78 ]Kv^l^_
output.writeLong(fileSplitterFetch.nEndPos); ;?q}98-2
} g4YlG"O[~
output.close(); !aKu9SR^e
} 2-jXj9kp`
catch(IOException e){e.printStackTrace ();} f~/hsp~Hp
catch(Exception e){e.printStackTrace ();} 7WY~v2SDF
} 1Kr$JIcd
agE-,
|=KzQY|u
//读取保存的下载信息（文件指针位置） f=VlOd
private void read_nPos() <Q"G aqZ
{ fK *l?Hr
try{ s:_a.4&Y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JYmYX-
int nCount = input.readInt(); '.<c[Mp
nStartPos = new long[nCount]; Gt _tL%
nEndPos = new long[nCount]; q'4P/2)va
for(int i=0;i<nStartPos.length;i++) fD3'Ye<R
{ !Q5,Zhgr
nStartPos = input.readLong(); hc3tzB
nEndPos = input.readLong(); U@CAQ?
} ob'" ^LO\
input.close(); #XB3Wden2
} *|y$z+g/
catch(IOException e){e.printStackTrace ();} WRwx[[e6z
catch(Exception e){e.printStackTrace ();} 87W!R<G
} uqU&k@
bsr]Z&9rrk
:I7mMy*
private void processErrorCode(int nErrorCode) `&h-+
{ R*0mCz^+h
System.err.println("Error Code : " + nErrorCode); ,zr,>^v
} 6 eu7&Kj'
0rz1b6F5,
*po o.Zz
//停止文件下载 l'@!'
public void siteStop() B3D}'<
{ YllZ5<}
bStop = true; MkjB4:"
for(int i=0;i<nStartPos.length;i++) "'@D\e}
fileSplitterFetch.splitterStop(); <SQR";
"\T-r2
RgJbM\`}?
} h::(b,|f7
} z^jmf_
//负责部分文件的抓取 +P Dk>PdEt
**FileSplitterFetch.java RAk"C!&^m
*/ HV-;?5
package NetFox; I8% -ii
HY1K(T
8x LXXB
import java.io.*; x}Lj|U$r<X
import java.net.*; pZlt4
]z8/S!?
Yw]$/oP`
public class FileSplitterFetch extends Thread { 6R^32VeK($
nw,.I [
jDTG15_=
String sURL; //File URL R4R\B
long nStartPos; //File Snippet Start Position K*2s-,b *
long nEndPos; //File Snippet End Position Mis B&Ok`k
int nThreadID; //Thread's ID nTGZ2C)c<'
boolean bDownOver = false; //Downing is over Vdefgq@<
boolean bStop = false; //Stop identical =Ul"{T<
FileAccessI fileAccessI = null; //File Access interface S.B?l_d^
nM:<l}~v{
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mMOgx
{ XP0;Q;WF}
this.sURL = sURL; R@s|bs?
this.nStartPos = nStart; i+in?!@G:
this.nEndPos = nEnd; !Q_Wbu\U
nThreadID = id; qyFeq])
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4c{j9mh
} 7FyE?
GnUD<P=I
[KHlApL
public void run() QV HI}3~
{ @1&"S7@}u
while(nStartPos < nEndPos && !bStop) ?u?mSO/
{ iAk.pH]a
m;hp1VO)
&+A78I
try{ I{>Z0+
URL url = new URL(sURL); :_:)S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o _l_Yi
httpConnection.setRequestProperty("User-Agent","NetFox"); 3 yb]d5:U
String sProperty = "bytes="+nStartPos+"-"; M%Rr=
httpConnection.setRequestProperty("RANGE",sProperty); zh0T3U0D
Utility.log(sProperty); >o{JG(Rn
F[%k;aJ
\P9ms?((A
InputStream input = httpConnection.getInputStream(); `''y,{Fs
//logResponseHead(httpConnection); }uC]o@/
UcD<vg"p
Ayg^<)JWh
byte[] b = new byte[1024]; SCe$v76p#
int nRead; b=\chCRJJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WQ8 "Jj?k6
{ WFV'^-4
nStartPos += fileAccessI.write(b,0,nRead); *`wz
//if(nThreadID == 1) ,%N[FZ`|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xP9h$!
} p=A,yGDV
u/S>*E
w xte
Utility.log("Thread " + nThreadID + " is over!"); |[mmEYc
bDownOver = true; <%%)C>l
//nPos = fileAccessI.write (b,0,nRead); Qk>U=]U
} !X$19"
catch(Exception e){e.printStackTrace ();} Xx[,n-rA
} }2e s"
} cuumQQ
rO.[/#p\
f(blqO.@l
//打印回应的头信息 u^|cG{i5"
public void logResponseHead(HttpURLConnection con) 4vN:Kj
{ 4ytdcb
for(int i=1;;i++) <fDT/
{ ^0cbN[~/ns
String header=con.getHeaderFieldKey(i); D_JGbNigA
if(header!=null) {47l1wV]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EK[J!~
Utility.log(header+" : "+con.getHeaderField(header)); `[#id@Z1
else P7,g^:$
break; Br}@Vvq@
} M&29J
} o3|4PAA/
X<Cfy
s !2Iui @
public void splitterStop() NyRa.hgZ;
{ t$Ff$(
bStop = true; jVN06,3z
} NQ[X=a8N
ty#6%
Zr2T^p5u
} \<`oW>
XR7v\rd
0&I*)Zt9x
/* Ly^bP>2i
**FileAccess.java )D/,QWk
*//文件访问(定位，写) w}OBp^V^
package NetFox; cUG^^3!
import java.io.*; l=l$9H,
,lvG5B\0
r"{jrBK$
public class FileAccessI implements Serializable{ l-v m`-_#
f -F}~S
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b/R7Mk1
RandomAccessFile oSavedFile; {'wvb "b
long nPos; =fnBE`Uc
aN07\
hbvcIGaT
public FileAccessI() throws IOException uHZ4 @w:
{ 6.KEe^[-
this("",0); ] L#c <0
} Jh&DL8`
P/1YN
1|xe'w{
public FileAccessI(String sName,long nPos) throws IOException D^m2iW;
{ 0?/gEr
oSavedFile = new RandomAccessFile(sName,"rw"); ^zO{Aks
this.nPos = nPos; 'fb\t,
oSavedFile.seek(nPos); FI?J8a
} !i (V.A
fi*b]a\'
< B]qqqP
public synchronized int write(byte[] b,int nStart,int nLen) jxkQ #Y
{ &uO-h
int n = -1; 9m2FH~
try{ w*/@|r39
oSavedFile.write(b,nStart,nLen); E%D.a=UX,
n = nLen; .0xk},
} <W8%eRfU
catch(IOException e) l P=I0A-
{ e<1Ewml(]
e.printStackTrace (); ?G',Qtz<K
} tl!dRV92
AQQa6Ce*
gM;m{gXYK
return n; DMch88W
} \SQ4yc
^(C4Q?[2m
3'0vLi
} >]ux3F3\
I)` +:+P
^VMCs/g6
/* j][&o-Ev
**SiteInfoBean.java XPMUhozV
*/ \C>IVz<O
package NetFox; ;K8}Yq9p9
rm3/R<
{X?1}5ry
public class SiteInfoBean { !<~.>5UQ
+ <E zv
:ZB.I(v
private String sSiteURL; //Site's URL %regt{
private String sFilePath; //Saved File's Path F4T!&E%6
private String sFileName; //Saved File's Name N]/cBGy
private int nSplitter; //Count of Splited Downloading File Km= Y^x0
)b]wpEFl
8g_kZ^<[
public SiteInfoBean() g.`Ntsi$wI
{//nSplitter的缺省值为5 sBI/`dGZV
//default value of nSplitter is 5 qQDe'f~
this("","","",5); 965x_ %
} svEe@Kt`
?32~%?m
Myg;2.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g7hI9(8+
{ m`8{arz2
sSiteURL= sURL; J>T98y/))
sFilePath = sPath; &XcPHZy'
sFileName = sName; z)^.ai,:0
this.nSplitter = nSpiltter; j~ds)dW%`&
GEVDXx>@
l\AdL$$Mb
} r`Fs"n#^-4
z;9D[ME#1
3zKeN:w
public String getSSiteURL() 6U8esPs,
{ sj/k';#g
return sSiteURL; Jv3G\9_
} Gchs$^1`t
1U/9=b
qP;1LAX
public void setSSiteURL(String value) RZ{O6~VH
{ Lks+FW
sSiteURL = value; [c1Gq)ht
} pl@K"PRE
G?,3Zn0
%Ul,9qG+
public String getSFilePath() .J @mpJdY
{ 'Y ,2CN
return sFilePath; T`]%$$1s
} sDg1nKw(
3p HI+a
?nL,Otz
public void setSFilePath(String value) L58H)V3Pn
{ 5p~5-_JX
sFilePath = value; G/3T0d+-
} @,,G]4zZ!
xWY\,'+Q
;Q vQ fV4
public String getSFileName() q#8\BOTP |
{ L|#0CRiN
return sFileName; zq$L[X
} uc"%uc'
Ue;Z)}
(r?hD*2r
public void setSFileName(String value) G+2fmVB*X
{ > fV"bj.
sFileName = value; .6rbn8h
} W-r^ME
^vSSG5 :
pV8tn!
public int getNSplitter() -"'+#9{h
{ o58c!44
return nSplitter; "S'Yn-
} +$>aT(q
K5`*Y@
g.62XZF@
public void setNSplitter(int nCount) qk^/&j
{ fsEQ4xN'
nSplitter = nCount; E6xdPjoWy
} hfbu+w):
} {0,6-dd5
*wJz0ex7R/
_(:$ :*@
/* vc3r [mT
**Utility.java "R)n1,0
*/ 9L-jlAo<
package NetFox; 1]0;2THx
5Zhl@v,L%
KCZ<#ca^
public class Utility { zXlerQWUv
jbZTlG
I~~":~&
public Utility() dJrUcZBr
{ CflyK@
6Ktq7'Z@
+{;wOQ.
} 1D[>oK\
&CXk=Wj
//线程睡眠 t&x\@p9
public static void sleep(int nSecond) 3jW&S
{ 4|cRYZj5
try{ W<^t2j'
Thread.sleep(nSecond); *6u2c%^
} znWB.H
catch(Exception e) TT3GGHR
{ PvW4%A@0
e.printStackTrace (); +CSv@ />3
} )+,h}XqlX
} $f+I#uJ
+zDRed_]=_
//日志 NB^Al/V@
public static void log(String sMsg) DS@Yto
{ RTg\c[=w
System.err.println(sMsg); S^D@8<6GJ
} <?DI!~
4=y&}3om(0
UB8n,+R
public static void log(int sMsg) _~umE/tz
{ 6q`)%"4k
System.err.println(sMsg); 8n2;47 a
} <f.Eog
} .dxELSV
>e-0A
w9"~NK8xzM
/* ;{R;lF,
**TestMethod.java jHHCJOHB8
*/ OA}; pQ9QN
package NetFox; Ke:EL;*8k
qvWi;
eYkg4O'
public class TestMethod { 5"1wz
_e8v12s
Hc|cA(9sh9
public TestMethod() )OQ<H.X
{ ///xx/weblogic60b2_win.exe ?0sTx6x@
try{ %Q}(.h%M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 74 )G.!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); X+u1p?
SiteFileFetch fileFetch = new SiteFileFetch(bean); %`]!atH
fileFetch.start(); 3PLA*n+%
} ,|zzq@fk
catch(Exception e){e.printStackTrace ();} Tz9 (</y
pJl/d;Cyrb
p0CPeH
} Lq.2vfA>
(IjM
km^ZF<.@
public static void main(String[] args) SS_6VE*sI
{ .ej+?QYwC
new TestMethod(); k5Q1.;fW76
} d9jD?HgM(
} sy4Nm0m
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