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)); go6;_
} (Lh!7g/0N
for(int i=0;i<nEndPos.length-1;i++) Df2$2VU
{ ^e_uprZWm
nEndPos = nStartPos[i+1]; JS\]|~Gd
} ,+OVRc
nEndPos[nEndPos.length-1] = nFileLength; 3rN}iSF^
} L_:~{jV
} &Y9%Y/Y
/GJL&RMx
p(4B"[!S
//启动子线程 `<T4En
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; doX`NbA
for(int i=0;i<nStartPos.length;i++) dikX_ Q>D
{ "mU2^4q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XJl 3\*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), yD!GgnW
nStartPos,nEndPos,i); 7iv g3*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ER&\2,fZ
fileSplitterFetch.start(); "9Q_lVI|Q
} E;4dlL`*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KC9VQeSc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Wq1OYZ,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YaQ5Z-c
nEndPos = " + nFileLength); d0%Wz5Np
// fileSplitterFetch[nPos.length-1].start(); fo>_*6i74
@J^ Oy 3z
vF@|cTRR)
//等待子线程结束 9Ou}8a?m"
//int count = 0; As^eL/m2L
//是否结束while循环 \YF;/KwX$
boolean breakWhile = false; N;}X$b5Y @
&io+*
bYhG`1,$-a
while(!bStop) Y![i=/
{ N 5{w
write_nPos(); tOk=m'aUK
Utility.sleep(500); Abmi=]\bx
breakWhile = true; @'hkU$N)
6Qz=g t%I=
E/1:4?1 S
for(int i=0;i<nStartPos.length;i++) +m~3InWq
{ qn{9vr
if(!fileSplitterFetch.bDownOver) EUgKJ=jw
{ OQg}E@LZ
breakWhile = false; }LEasj
break; Lew 2Z
} ^K~=2^sh
} `@6y Wb:X
if(breakWhile) ZN'B@E=p
break; }+u<w{-7/
D6yE/QeK4
wA,-!m
//count++; &g*1If
//if(count>4) .]<iRf[\[
// siteStop(); Gcxz$.(
} C4dCaiX
G$/Qcr6W<
C4-%|+Q i
System.err.println("文件下载结束！"); 9&B#@cw
} qI74a F
catch(Exception e){e.printStackTrace ();} x @9rc,by
} Lke!VS!P&
2*n~r
Ib/e\+H\
//获得文件长度 z<yqQ[
public long getFileSize() 7o*~zDh@fH
{ 3_i29ghv
int nFileLength = -1; &wkbr2P
try{ (Nf!E[}Z
URL url = new URL(siteInfoBean.getSSiteURL()); wYv++< z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %(\et%[]
httpConnection.setRequestProperty("User-Agent","NetFox"); n{m[ j+UG
sVnpO$
=6fJUy^M\
int responseCode=httpConnection.getResponseCode(); H:z<]Rc
if(responseCode>=400) UhU+vy6)/
{ :2A-;P4
processErrorCode(responseCode); a`C2:Z23(#
return -2; //-2 represent access is error nx{X^oc8e
} rC/z8m3z
)U}`x }:,
<]`|HJoy
String sHeader; ,n>K$
;__k*<+{.
6s!=de
for(int i=1;;i++) +J42pSxzoo
{ bNvc@oo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ej(< Le\
//Utility.log(in.readLine()); `'bu8JK
sHeader=httpConnection.getHeaderFieldKey(i); 1u }2}c|
if(sHeader!=null) {HVsRpNEf
{ |F~U
if(sHeader.equals("Content-Length")) "p>kiNu
{ $ 93j;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b'`C<Rk
break; /}d)g4\j
} H$zDk
} m'ZxmsFo
else ehMpo BL
break; b0N7[M1Xl
} h?->A#
} QbWeQ[V{
catch(IOException e){e.printStackTrace ();} )fke;Y0
catch(Exception e){e.printStackTrace ();} i>pUTT _[
mJVru0
1n>AN.nI
Utility.log(nFileLength); Q$yQ^ mG
{q);1Nnf
W{]r_`=:6S
return nFileLength; .SWn/Kk
} OZ<fQf.Gh}
AC?a:{./
+KP&D.wIo
//保存下载信息（文件指针位置） 2>^jMln
private void write_nPos() 97}l`z;Z
{ .&KC2#4
try{ O%} hNTS"
output = new DataOutputStream(new FileOutputStream(tmpFile)); @< 0c
output.writeInt(nStartPos.length); 1w 9zl}
for(int i=0;i<nStartPos.length;i++) }ol<DV
{ G98fBw
// output.writeLong(nPos); IfCa6g<&(
output.writeLong(fileSplitterFetch.nStartPos); EPEn"{;U
output.writeLong(fileSplitterFetch.nEndPos); I$fm"N
} =u5( zaBe
output.close(); R]S!PSoL
} fQ2U|
catch(IOException e){e.printStackTrace ();} lt0byn$vz
catch(Exception e){e.printStackTrace ();} LdX'V]ITh
} StLbX?d6
AASS'H@
!F$o$iq
//读取保存的下载信息（文件指针位置） 92/_!P>
private void read_nPos() aSfAu!j)
{ Nqbm,s
try{ [ofZ1hB4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >H]|R }h
int nCount = input.readInt(); Xh*NuHH
nStartPos = new long[nCount]; r{Z4ifSl(
nEndPos = new long[nCount]; zhI"++
for(int i=0;i<nStartPos.length;i++) 0T:U(5Y9
{ 5^{).fig
nStartPos = input.readLong(); #\3X;{
nEndPos = input.readLong(); ev5m(wR
} 0P4g6t}e
input.close(); N8{ 8 a
} )gxZ &n6
catch(IOException e){e.printStackTrace ();} eqU y>
catch(Exception e){e.printStackTrace ();} R, UYwI
} 7)x788Z6
F||oSJrI
!z+'mF?V+X
private void processErrorCode(int nErrorCode) -&LF`V&3w
{ x0dBg~I
System.err.println("Error Code : " + nErrorCode); .JWN\\
} 6{[uCxxl
KzZRFEA_
$< .wQ8:Q
//停止文件下载 Mg\8m-L^
public void siteStop() G,@Jo[e
{ /+?eSgM/
bStop = true; kclZ+E
for(int i=0;i<nStartPos.length;i++) Y\9zjewc
fileSplitterFetch.splitterStop(); ?Pt*4NaT;
p{O@ts:
~Z;.np(T
} p3cb_
} 1Zgv+.
//负责部分文件的抓取 %Lfy!]Ru
**FileSplitterFetch.java F@-8J?Hl:
*/ VVi3g
package NetFox; :io[9B [
>q1rdq
\{}5VVw-S?
import java.io.*; r]bG,?|
import java.net.*; #>">fs]
N/8B@}@n
+)*oPSQ5
public class FileSplitterFetch extends Thread { k6|/ik9C
7,R ~2ss5z
cg}lF9;d
String sURL; //File URL zw%1a 3!
long nStartPos; //File Snippet Start Position >u?a#5R:m
long nEndPos; //File Snippet End Position b}m@2DR'|m
int nThreadID; //Thread's ID L&Pj0K-HT3
boolean bDownOver = false; //Downing is over )bB Va^
boolean bStop = false; //Stop identical V`"Cd?R0Z
FileAccessI fileAccessI = null; //File Access interface d+IN-lR(
#9]O92t2UV
<*db%{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F<Z13]|
{ idY Xv)R
this.sURL = sURL; +-MieiKv
this.nStartPos = nStart; _>Oc>.MB
this.nEndPos = nEnd; qGECw#
nThreadID = id; D4U<Rn6N_5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ak,T{;rD
} )3)fq:[
9_J'P2e
d@+u&xrd
public void run() *XluVochrb
{ NV;T*I8O
while(nStartPos < nEndPos && !bStop) L=kETJ:g
{ $`"$ZI6[
)$QZ",&5
\|C~VU@
try{ {:`XhPS<B
URL url = new URL(sURL); YZ/2:[b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;b0;66C8|
httpConnection.setRequestProperty("User-Agent","NetFox"); )bK3%>H#
String sProperty = "bytes="+nStartPos+"-"; m~8=?R+m
httpConnection.setRequestProperty("RANGE",sProperty); ;1Q@d
Utility.log(sProperty); mC!^`y)
fOz.kK[]
FLaj|Z~#)
InputStream input = httpConnection.getInputStream(); wRe2sjM
//logResponseHead(httpConnection); Ca#T?HL
:2AlvjvjZ
Qsr+f~"W
byte[] b = new byte[1024]; \-{2E
int nRead; ]?0]K!7Ea
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n<DZb`/uHZ
{ @6{F4
nStartPos += fileAccessI.write(b,0,nRead); !'kr:r}gg
//if(nThreadID == 1) ;^ YpQP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u'Z^|IVfo
} 88A,ll%
{6HgKI
Fz@U\\94z
Utility.log("Thread " + nThreadID + " is over!"); V_jGL<X|
bDownOver = true; kQO5sX$;
//nPos = fileAccessI.write (b,0,nRead); He}"e&K
} h%Uq
catch(Exception e){e.printStackTrace ();} (T=u_oe
} dRXrI
} LCok4N$o
D #C\| E:
c) _u^Dh
//打印回应的头信息 Twpk@2=l
public void logResponseHead(HttpURLConnection con) '$q3Ze
{ q 7hoI]
for(int i=1;;i++) G3.\x_;k
{ So}pA2[0
String header=con.getHeaderFieldKey(i); $~'G<YYF4
if(header!=null) Ej$oRo{IG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^ARkjYt
Utility.log(header+" : "+con.getHeaderField(header)); @{@)gE
else cs)R8vuB)z
break; OZ2faf
} 6Q}>=R^h
} ;rt\
Y|-:z@n6C
|uM(A~?
public void splitterStop() Fuo.8
{ ,gIeQ!+vy
bStop = true; OwLJS5r@<-
} fTd":F
C0H@
WM GiV
} j&`D{z-c~
Eg$Er*)h8
;tfGhHpQn
/* @Zfg]L{Lr
**FileAccess.java 6\6g-1B`
*//文件访问(定位，写) DU:+D}vl
package NetFox; #QiNSS
import java.io.*; %m "9 =C
E4xybVo@
__)"-\w-_(
public class FileAccessI implements Serializable{ ,~XAV ;+
G+K`FUNA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -8&P1jrI
RandomAccessFile oSavedFile; , 4@C%
long nPos; 4YCuO%
j/hm)*\io
68nPz".X
public FileAccessI() throws IOException UX)QdT45Mh
{ 2o~UA\:+=
this("",0); e(jD[q
} "_ON0._(/
Ob|v$C
9zaSA,}
public FileAccessI(String sName,long nPos) throws IOException 7lG,.W|
{ Hx ojxZwm
oSavedFile = new RandomAccessFile(sName,"rw"); 6V-JyTcxGI
this.nPos = nPos; j +Ro?
oSavedFile.seek(nPos); QMwV6cA
} |S3wCG
[V41 Gk
l/56;f\IA
public synchronized int write(byte[] b,int nStart,int nLen) Bx0=D:j
{ _>G=xKA#e
int n = -1; M>@PRb:Oc
try{ +e&Q<q!,q
oSavedFile.write(b,nStart,nLen); f&C]}P
n = nLen; aTE;Gy,W
} O,0j+1?
catch(IOException e) `&SBp }W}
{ <Mf(2`T
e.printStackTrace (); ^PowL:
} ?cgb3^R'
29f4[V X
/^,/o
return n; |/!RN[<
} 7'R7J"sY`|
gHVD,Jr
lF)k4 +M
} 13/U4-%b2
FyRr/0C>
J%8hf%!ud
/* l,ra24
**SiteInfoBean.java d 2z!i^:
*/ r%%<
package NetFox; (sEZNo5n
i^V3u
fs*OR2YG7
public class SiteInfoBean { +}NQ|y V
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X/23 /_~L`
private String sSiteURL; //Site's URL =[`gfw
private String sFilePath; //Saved File's Path QE`u~
private String sFileName; //Saved File's Name UsdUMt!u
private int nSplitter; //Count of Splited Downloading File Tywrh9[
iU4Z9z!
_&PF(/w
public SiteInfoBean() 5>~q4t)6z}
{//nSplitter的缺省值为5 ~lH2#u>g
//default value of nSplitter is 5 0]l9x}
this("","","",5); I.)9:7
} ':|?M B
M.KXDD#O
>RKepV(X7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (z X&feq
{ [P%'p-Hg_
sSiteURL= sURL; WsR4)U/]v
sFilePath = sPath; ^-7-jZ@jz
sFileName = sName; wO"ezQ
this.nSplitter = nSpiltter; >TS=tK
8PvO_Gz5
q:G3y[ P
} sW!MVv
9,0}}3J
9v76A~~
public String getSSiteURL() c_syJ<
{ y?8V'.f|
return sSiteURL; Fzn#>`qG
} _)^`+{N<
;e\K8*o
qF4DX$$<
public void setSSiteURL(String value) _H$Z}2g<z
{ )Tad]Hd"W
sSiteURL = value; K?,`gCN}v
} Hv|(V3-
Cj#?Z7}z
*jo1?
public String getSFilePath() )iCg,?SSw=
{ a}7P:e*u
return sFilePath; r8[Ywn<u
} k1;Jkq~
[N1[khY`
UQCond+K
public void setSFilePath(String value) *AA78G|
{ a,\GOy(q{
sFilePath = value; +(vL~
} KPI[{T\`ZM
vQDkZ
u9%AK g}~
public String getSFileName() &Ef6'
{ ;($ 3,d8
return sFileName; t)b /c:ql
} 6>-Gi
+g8uV hC
8'Q1'yc
public void setSFileName(String value) 1xMD )V:
{ LQ4F/[1}
sFileName = value; rOXh?r
} $ 7uxReFZR
S-G#+Ue2
mNr<=Z%b
public int getNSplitter() t[x[X4
{ 8Nxyc>8K~
return nSplitter; *G;D u`;
} dV+GWJNNE
LZrkFkiC
(JeRJ4
public void setNSplitter(int nCount) _ +A$6l
{ K@;ls
nSplitter = nCount; q<?r5H5
} T!gq Z
} ^HNccr
0vdnM8N2
*Y- rEF>
/* d,%@*v]S
**Utility.java cUM#|K#6
*/ Fj0h-7L
package NetFox; 9Q*zf@w
9NcC.}#-5
=s[P =dU
public class Utility { {$^Lb4O[V
/R)(u@jk
,v*<yz/
public Utility() d)jX%Z$LC
{ dG'5: ,n/
aW#_"Y}v'
^tKJ}}
} K9f7,/
&\s>PvnquX
//线程睡眠 %#b+ =J
public static void sleep(int nSecond) ^tFgkzXm
{ YM]ZL,8
try{ NpF}~$2
Thread.sleep(nSecond); }8&L?B;90
} O8S"B6?$~'
catch(Exception e) j8#B
{ >l|dLyiae
e.printStackTrace (); K>fY9`Whm
} @ei:/~y3
} +Ek('KOF
vt-53fa|
//日志 b-,]21
public static void log(String sMsg) .6#Y-iJqc
{ ;l'kPUv([
System.err.println(sMsg); ,R;wk=k
} 'Z(4Wuwb
=8)q-{p3
IEJp!P,E
public static void log(int sMsg) IOi6' 1l
{ B|+tK
System.err.println(sMsg); S)d_A
} rJl'+Ae9N|
} #y%?A;
[sH[bmLR
JK9}Kb};
/* YKs^aQm#
**TestMethod.java 9oA.!4q
*/ XDi[Iyj
package NetFox; $N1UEvC%Q
2KC~;5
(J^2|9r
public class TestMethod { ;l6tZ]-"
zSFqy'b.M-
xlWTHn!j
public TestMethod() U i ~*]
{ ///xx/weblogic60b2_win.exe x9!vtrM\Zr
try{ ,ZLg=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7`f',ZK%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y-c2tF@'v
SiteFileFetch fileFetch = new SiteFileFetch(bean); &D 4Ci_6k
fileFetch.start(); _GK3]F0
} kGSB6
catch(Exception e){e.printStackTrace ();} H:HJHd"W
L'Fy\K\
A_WtmG_9
} *FT )`
bqDHLoB\1
Hc{0O7
public static void main(String[] args) qSWnv`hL
{ pZ4]oK\*
new TestMethod(); X%b.]A
} va/$dD9
} R_2JP C
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