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)); \f /!
} o%/-5-
for(int i=0;i<nEndPos.length-1;i++) ?`N57'iPb
{ #Cg}!38
nEndPos = nStartPos[i+1]; '&.)T2Kw
} Mz/]DJ8
nEndPos[nEndPos.length-1] = nFileLength; v9t47>V
} -'O Q-5
} f!M[awj%
TbKP8zw{
5#TrCPi6A
//启动子线程 xfV,==uF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H9Y2n 0
for(int i=0;i<nStartPos.length;i++) QD.zU/F~>
{ IdV,%d{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (C-,ljY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [):{5hMA
nStartPos,nEndPos,i); ;NiArcAS!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); } * ?n?'
fileSplitterFetch.start(); DEUd[
} u%6Irdx
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %XEKhy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E3~,+68U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5+e>+$2
nEndPos = " + nFileLength); %sOWg.0_
// fileSplitterFetch[nPos.length-1].start(); #dva0%-1
LJRg>8
g9yaNelDh)
//等待子线程结束 &\;<t,3A~
//int count = 0; Hv8SYQ|
//是否结束while循环 Od0S2hHO
boolean breakWhile = false; xoqiRtlY:
*'UhlFed
d&}pgb-Md
while(!bStop) +R|U4`12
{ &Q\_;
write_nPos(); 5SoZ$,a<e
Utility.sleep(500); E S#rs="
breakWhile = true; Yw6DJY
k_,MoDz
A)\>#Dv
for(int i=0;i<nStartPos.length;i++) V~/.Y&WN
{ 'M~BE\
if(!fileSplitterFetch.bDownOver) 7%{R#$F
{ 6BDt.bG
breakWhile = false; iLF^%!:X%
break; xj0cgK|!
} /SnynZ.q
} \n[ 392
if(breakWhile) 6exRS]BI
break; <A)+|Y"^h6
%4j&H!y-w;
?QGmoQ)
//count++; z)5S^{(
//if(count>4) Qm $(
// siteStop(); o[o:A|n
} M(qxq(#{U
. 3GnZR,L
kt:)W])V
System.err.println("文件下载结束！"); }<SNO)h3
} \;-qdV_JB
catch(Exception e){e.printStackTrace ();} ?$3r5sx
} Am=wEu[b
K>kLUcC7Z
lY.B
//获得文件长度 J2r1=5HS
public long getFileSize() +)gGs#2X
{ (B&h;U$HAH
int nFileLength = -1; z/S,+!|z
try{ 2 #KoN8%
URL url = new URL(siteInfoBean.getSSiteURL()); .Y!:x=e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B#]_8svO
httpConnection.setRequestProperty("User-Agent","NetFox"); =HMmrmz:
,*dzJT$k
Kh)FyV
int responseCode=httpConnection.getResponseCode(); `|]e6Pb
if(responseCode>=400) Uh.Sc:trA
{ en>9E.?N
processErrorCode(responseCode); e&2wdH&
return -2; //-2 represent access is error _Fizgs
} CN/IH
=O,JAR"ug
W}h|K:-S
String sHeader; !h>D;k6 e
a\pi(9R
('t kZt%8
for(int i=1;;i++) S8%n.<OB
{ %,|ztH/ Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5@ foxI
//Utility.log(in.readLine()); &3Tx@XhO
sHeader=httpConnection.getHeaderFieldKey(i); J3G7zu8
if(sHeader!=null) kJkxx*:u
{ Fd7*]a
if(sHeader.equals("Content-Length")) (;}tf~~r
{ , H2YpZk
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Pd~MiyO;K
break; ID4~Gn
} -4flV D
} 6e.v&f7(
else ,)h)5o(?
break; Fc8E Y*
} %9o+zg? RJ
} MdC<4^|
catch(IOException e){e.printStackTrace ();} i"HgvBHx
catch(Exception e){e.printStackTrace ();} ~O: U|&
5j eO"jB
2yKz-"E
Utility.log(nFileLength); F>+2DlA`<e
NP/>H9Q2%
5+P@sD
return nFileLength; \DA$6w\\
} !gH9ay
8~ #M{}
Z0ReWrl;`
//保存下载信息（文件指针位置） n#*`!#
private void write_nPos() u1cu]Sj0
{ #SkX@sl@
try{ (9$"#o
output = new DataOutputStream(new FileOutputStream(tmpFile)); *Oo &}oAj
output.writeInt(nStartPos.length); Y ?'tUV
for(int i=0;i<nStartPos.length;i++) :gI.l1
{ b2kWjg.4
// output.writeLong(nPos); 5HlWfD
output.writeLong(fileSplitterFetch.nStartPos); u+D[_yd^
output.writeLong(fileSplitterFetch.nEndPos); s_eOcm
} ZPO|<uR
output.close(); 1H{jy^sP7
} otr>3a*'
catch(IOException e){e.printStackTrace ();} 7Kf}O6nE
catch(Exception e){e.printStackTrace ();} V U~Dk);Bv
} 61_f3S(u
Veji^-0E
w([$@1]
//读取保存的下载信息（文件指针位置） [@"wd_f{l
private void read_nPos() z.)p P'CJo
{ -<N&0F4|*
try{ I*\^,ow
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #cKqnk
int nCount = input.readInt(); PRs@zkO
nStartPos = new long[nCount]; Ec]|p6a3
nEndPos = new long[nCount]; I@ \#up}
for(int i=0;i<nStartPos.length;i++) o-eKAkh
{ #^rU x.
nStartPos = input.readLong(); 1 W'F3
nEndPos = input.readLong(); SEF6B45}1
} YQ(Po!NI\'
input.close(); $.K?N@(W
} GsV4ZZ
catch(IOException e){e.printStackTrace ();} ZR3nK0
catch(Exception e){e.printStackTrace ();} P $>`
} HJhH-\{@
c-CYdi@
sR_xe}-
private void processErrorCode(int nErrorCode) Imym+
{ IcF@F>>
System.err.println("Error Code : " + nErrorCode); ;Zut@z4\
} OXhAha`R
>+9JD%]x]
N$alUx*
//停止文件下载 py<_HyJ
public void siteStop() 'ks{D(`
{ &__DJ''+
bStop = true; P-Su5F
for(int i=0;i<nStartPos.length;i++) Z(Q2Ue;}&
fileSplitterFetch.splitterStop(); ,Og4 ?fS
M##';x0
*\XH+/]+
} z&+ zl6
} YD[H
//负责部分文件的抓取 e~\QE0Oe:
**FileSplitterFetch.java yTAvF\s$(
*/ d'HOpJE
package NetFox; RA/EpD:H
wNQqfqZ
zFhgE*5
import java.io.*; 6rDfQ`f\p
import java.net.*; iI?{"}BZ
[aW=
:jem~6i
public class FileSplitterFetch extends Thread { `y!/F?o+!
m *X7T
kU*{4G|6
String sURL; //File URL UQ8bN I7
long nStartPos; //File Snippet Start Position 'fW#7W
long nEndPos; //File Snippet End Position /oP^'""@je
int nThreadID; //Thread's ID Tj/GClD:%
boolean bDownOver = false; //Downing is over 4\2V9F{s
boolean bStop = false; //Stop identical ^^?q$1k6r*
FileAccessI fileAccessI = null; //File Access interface `rFAZcEj%
2VgP
\C|cp|A*&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1(gfdx9|b
{ v%91k
this.sURL = sURL; jj&s}_75
this.nStartPos = nStart; 9K"JYJ q2
this.nEndPos = nEnd; ;u-4KK
nThreadID = id; i^2IW&+}e}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8<&EvOk
} i@$*Csj\9*
sa#.l% #
5M){!8"S)#
public void run() O!F]^'!
{ k onoI&kV|
while(nStartPos < nEndPos && !bStop) f`P9ku#j}
{ oyeG$mpg
CEtR[Cu
hC<14
try{ nWgv~{,x
URL url = new URL(sURL); t1i(;|8|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ')TPF{\#
httpConnection.setRequestProperty("User-Agent","NetFox"); 3LK%1+)4
String sProperty = "bytes="+nStartPos+"-"; +=fKT,-*G!
httpConnection.setRequestProperty("RANGE",sProperty); e3(<8]`b[
Utility.log(sProperty); %}qbkkZ
{NQoS"
vXcy#
InputStream input = httpConnection.getInputStream(); fE25(wCz7
//logResponseHead(httpConnection); ?[= U%sPu=
*xH\)|3,
SkP[|g'56
byte[] b = new byte[1024]; bBE+jqi2
int nRead; F!g;A"?V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5Pke8K
{ Spj9H?m
nStartPos += fileAccessI.write(b,0,nRead); WZ~> BM
//if(nThreadID == 1) ]PX}b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \{v,6JC
} [)|+F wJ
ElR)Gd_8
KD*O%@X5C
Utility.log("Thread " + nThreadID + " is over!"); ~j&?/{7I
bDownOver = true; 2Rptxb_@
//nPos = fileAccessI.write (b,0,nRead); 6 =>G#
} J r*"V`
catch(Exception e){e.printStackTrace ();} <GZhH:
} ,"G\f1
} ,2zKQ2z
{bkGYx5.C
Fd8hGj1
//打印回应的头信息 Yj8&
public void logResponseHead(HttpURLConnection con) u0]q`u/T
{ F`&>NQb
for(int i=1;;i++) w}k B6o]
{ fusPMf *[
String header=con.getHeaderFieldKey(i); r{ @ `o@q
if(header!=null) O@,i1ha%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &?T${*~
Utility.log(header+" : "+con.getHeaderField(header)); x0G>ktWq<
else z,+m[x=/N
break; |- OHve4A
} 4#2 ,Y!
} 5 ,ZRP'oI
Oz>io\P94
Q8Te'1Ln!
public void splitterStop() :,YLx9i>
{ 'j#a%j@{
bStop = true; -$R5
} ^[TOZXL`:
z7q%,yw3N
<^sAY P|
} VjTAN=
sT1jF3
k2uBaj]
/* \e0x,2
**FileAccess.java *a4 b
*//文件访问(定位，写) qKs7WBRJy
package NetFox; :BDviUC7Z
import java.io.*; OfLM
rgn|24x
?,V;f2c
public class FileAccessI implements Serializable{ 05g?jV
c#x7N9;"!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [Ekgft&
RandomAccessFile oSavedFile; ULrbQ}"cva
long nPos; F]SIT\kBm
w6v1 q:20
hhj ,rcsi
public FileAccessI() throws IOException J\GKqt;5@
{ Nc:U4
this("",0); BGYm]b\j[
} V<I${i$]0
~G^doj3|+
X#C7r@H
public FileAccessI(String sName,long nPos) throws IOException P VW9iT+c
{ aV%rq9Tp
oSavedFile = new RandomAccessFile(sName,"rw"); /XK`v=~(l{
this.nPos = nPos; 49kia!FR
oSavedFile.seek(nPos); *X55:yha
} xb_:9
E|#R0n*
Wb(0Szk;
public synchronized int write(byte[] b,int nStart,int nLen) <"P '"SC
{ c|a|z}(/J
int n = -1; Hjkgy%N
try{ 0cU^ue%
oSavedFile.write(b,nStart,nLen); $ T_EsnN
n = nLen; (:muxby%
} 31;T$5v1
catch(IOException e) ;;H:$lx
{ DfFPGFv
e.printStackTrace (); ?pY!sG
} {j@)sDMX
1g.9R@Kc$
LX&P]{qKS
return n; JNl+UH:.
} uQ1;+P:L
mwhn=y#]*
J8DbAB4X
} Qeog$g.HI
x)5v8kgf
=^M t#h."
/* }w8AnaC
**SiteInfoBean.java <}1%">RA
*/ 9Q1GV>j>B
package NetFox; M.Ik%nN#K0
+yI^<BH
F'*&-l
public class SiteInfoBean { =*U24B*U93
cyE2=
%%[TM(z
private String sSiteURL; //Site's URL h;M2ylOu.
private String sFilePath; //Saved File's Path K~>kruO";
private String sFileName; //Saved File's Name AtOB'=ph*
private int nSplitter; //Count of Splited Downloading File Dr:}k*
{cA )jW\'
~Zm(p*\T
public SiteInfoBean() w[ngkLEA
{//nSplitter的缺省值为5 Yt^+31/%
//default value of nSplitter is 5 ceCshxTU
this("","","",5); 2srz) xEe
} {Hv=iVmt
4 #N#[;M
L%"Mp(gZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "=;&{N~8U
{ ov~m?Y]h
sSiteURL= sURL; N\?iU8w=
sFilePath = sPath; ?8 F7BS4oQ
sFileName = sName; ZU|nKt<GK
this.nSplitter = nSpiltter; Fk43sqU6~
cPXvTVvs
e_TM#J(3
} @b zrJ7$
)+G(4eIT
M: 6cma5
public String getSSiteURL() LtQy(F%8/
{ ^cNP?7g7
return sSiteURL; lV?SvXe
} }bVyvH
L0Cf@~k
cg~FW2Q
public void setSSiteURL(String value) ]V_9[=%
{ ]~P?
sSiteURL = value; =h)H`
} s$en5)
BSz\9 eT
|z~?"F6 Y<
public String getSFilePath() yZ{YIy~
{ ,y.0Cb0
return sFilePath; %lPP1 R
} xR.Ql>
y+PukHY
,'j5tU?c
public void setSFilePath(String value) ,P|PPx%@
{ c(jA"K[|b
sFilePath = value; !EFd-fk
} X[w9~t$\
s{/nO)
Q3DxjD
public String getSFileName() P(4[<'HO
{ EW`3h9v~
return sFileName; j\a?n4g -
} EPI*~=Z.U
&ke4":7X
Oe273Y^e
public void setSFileName(String value) )):22}I#
{ <ivqe"m
sFileName = value; &Dg)"Xji
} pG F5aF7T
RJ}yf|d-C
2u*h*/
public int getNSplitter() C6^j#rl
{ @i1q]0
return nSplitter; ab4LTF|
} >r}Vf9 5[N
4ZI_pf
h(N=V|0
public void setNSplitter(int nCount) M-Sv1ZLh
{ 6+PGwCS
nSplitter = nCount; 38Efp$)
} hW' HT
} ~L'nzquF
XTo8,'UaP
O-!,Jm
/* ],&\%jd<
**Utility.java ;J=:IEk
*/ aR)?a;}H
package NetFox; c#pj:f*H
d+5:Qrr
Sk=N [hwU
public class Utility { ~ 5"J(
X4Xf2aXI
LdEE+"Jw
public Utility() 6K 4+0xXv
{ p;`N\.ld
sFElD ]|
4bI*jEc\[
} QJSr:dP4dG
* nCx[
//线程睡眠 'vlrc[|/
public static void sleep(int nSecond) oEIqA
{ $?f]ZyZr.
try{ 9v~5qv;
Thread.sleep(nSecond); IG|\:Xz
} x'i0KF
catch(Exception e) wd+O5Lr.R
{ sX'nn
e.printStackTrace (); 2AK}D%jfc
} Qlh?iA
} >'Hx1;
\EI#az=I
//日志 o#}mkE87
public static void log(String sMsg) r*Z_+a8
{ g;G5 r&T
System.err.println(sMsg); |Puj7Ru
} fIkT"?
hr~.Lj5^W
<kbnu7?a*
public static void log(int sMsg) B5`;MQJ
{ F*\4l;NJ
System.err.println(sMsg); Z= ik{/
} f?-J#x)
} ^ZVOql&
<<<NXsH
e~ BJvZ}Q
/* bd{\{[^S!
**TestMethod.java {u4i*udG`)
*/ EL +,jrU~
package NetFox; b9#m m
Z@oKz:U
vX.]hp5~
public class TestMethod { 8]]@S"ZM,\
ArX]L$D
cNeiD@t3V&
public TestMethod() ^'YHJEK
{ ///xx/weblogic60b2_win.exe }VZM,.w
try{ D6:DrA:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); niAZ$w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b"3uD`
SiteFileFetch fileFetch = new SiteFileFetch(bean); 07Y_^d
fileFetch.start(); >uW^.e "F
} z L8J`W
catch(Exception e){e.printStackTrace ();} |?yE^$a
g/B\ObY
QH:>jmC{1h
} O$U}d-Xnx
C$_G'XI
bq: [Nj
public static void main(String[] args) ph+M3q(z
{ $':JI#
new TestMethod(); HoL~j({
} ka8$dfC
} ;/R kMS
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