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)); A;e0h)F$-
} <rAWu\d;
for(int i=0;i<nEndPos.length-1;i++) 6"PwOEt
{ n^:Wc[[m
nEndPos = nStartPos[i+1]; +E8}5pDt
} e_z"<yq
nEndPos[nEndPos.length-1] = nFileLength; ^e4y:#Nu
} e,rCutA)
} QCVwslj,K
ppXt8G3%x
w?Nx^)xX
//启动子线程 q@8j[15
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Yt#e[CYnu
for(int i=0;i<nStartPos.length;i++) 81&5g'
{ r5(-c]E7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [2Rw)!N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xGVL|/?8
nStartPos,nEndPos,i); 1 6G/'Hb
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9<Kc9Z
fileSplitterFetch.start(); p&<X&D
} v.pj PBU1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }Pf7YuUZZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #M5[TN!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Tt*n.HA
nEndPos = " + nFileLength); (U#9
// fileSplitterFetch[nPos.length-1].start(); DX)T}V&mP
Z2soy-
7\p<k/TS
//等待子线程结束 +'f38D*
//int count = 0; '@ C\,E
//是否结束while循环 pGhA
boolean breakWhile = false; 3t^r;b
RiNKUk{-
j_Z"=
while(!bStop) ^d[s*,i?
{ p@x1B &Z
write_nPos(); hp6%zUR
Utility.sleep(500); wU=@,K
breakWhile = true; 2 bQC2
{S;/+X,
}iF"&b0n"
for(int i=0;i<nStartPos.length;i++) vJE>H4qPmD
{ JJe?Zu\
if(!fileSplitterFetch.bDownOver) %U$PcHOo
{ J;S@Q/s
breakWhile = false; is,r:
break; ]/C1pG*o
} yg-uL48q
} `fUem,$)1F
if(breakWhile) <D!\"C
break; $xU5vCwAo
KN"V(<!)~
#7~i.8L
//count++; |[]"{Eo"}
//if(count>4) 2n`OcXCh/
// siteStop(); #Kp/AN5YC
} oztfr<cUH
/92m5p
|K%nVcR=
System.err.println("文件下载结束！"); WF{rrU:
} Gj}P6V_
catch(Exception e){e.printStackTrace ();} BHW8zY=F
} XCTee
s]p3dB#
B{0m0-l
//获得文件长度 RO1xcCp
public long getFileSize() 9G'Q3? z
{ 5$ra4+k0
int nFileLength = -1; e2?7>?
try{ !SFF 79$c
URL url = new URL(siteInfoBean.getSSiteURL()); R;*3";+v|:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N>$Nw<wV
httpConnection.setRequestProperty("User-Agent","NetFox"); t6)wR
,Uh7Q-vd
kN)m"}gX
int responseCode=httpConnection.getResponseCode(); Y:0SrB!\
if(responseCode>=400) fEl,jA
{ 4Fr\=TX
processErrorCode(responseCode); fem>WPvG
return -2; //-2 represent access is error ~Z'3(n*9
} |<n+6
k8;
D%0GXUp
String sHeader; W&U Nk,
=N9a!ii|
K] ^kUN_
for(int i=1;;i++) M)U 32gI:
{ HZ1e~IIw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @qfVt
//Utility.log(in.readLine()); )&j4F)
sHeader=httpConnection.getHeaderFieldKey(i); 7O)U(<70
if(sHeader!=null) [8VB"{{&
{ TuBl9 p'6
if(sHeader.equals("Content-Length")) ]tVU$9D
{ tCk;tu!d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ">G|\_ZF
break; Vc!;O9dP
} 'j)xryw
} 0.~Pzg
else L{)e1p]q
break; !6pOY*> j
} FX FTf2*T
} xsx @aF
catch(IOException e){e.printStackTrace ();} 62&(+'$n
catch(Exception e){e.printStackTrace ();} Ew=8"V`C
8/;q~:v
OgiElA.
Utility.log(nFileLength); \S)\~>.`y!
NY'sZTM&
(o1*7_]e
return nFileLength; >C`b4xQ
} 1A4!zqT;
K.Tfu"6
;J~NfL
//保存下载信息（文件指针位置） 1Z +3=$P
private void write_nPos() [=Y@Ul
{ g3%Xh0007{
try{ k;w1y(
output = new DataOutputStream(new FileOutputStream(tmpFile)); `4RraJj>0~
output.writeInt(nStartPos.length); @N,EoSb :
for(int i=0;i<nStartPos.length;i++) $#g1Mx{
{ <|NP!eMsw8
// output.writeLong(nPos); 4eym$UWw
output.writeLong(fileSplitterFetch.nStartPos); X=Q)R1~6v
output.writeLong(fileSplitterFetch.nEndPos); :!M/9D*}0
} #ra~Yb-F
output.close(); VfJYYR
} vs/.'yD/C
catch(IOException e){e.printStackTrace ();} vr|9NP]v
catch(Exception e){e.printStackTrace ();} !_VKJZuH
} Lt+ Cm$3
X ?/C9
h&+dIk\[3
//读取保存的下载信息（文件指针位置） Ji_3*(
private void read_nPos() 3[E3]]OVa
{ u=h:d+rq@
try{ kzG mDi
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {$,e@nn
int nCount = input.readInt(); :A\8#]3
nStartPos = new long[nCount]; ~a:0Q{>a
nEndPos = new long[nCount]; 8. [TPiUn'
for(int i=0;i<nStartPos.length;i++) 8,pnm
{ hBf0kl
nStartPos = input.readLong(); Fu0 dYN
nEndPos = input.readLong(); NKD<VMcqw
} :?s~,G_*l
input.close(); M-3kF"
} d0y [:
catch(IOException e){e.printStackTrace ();} CA)DQYp{
catch(Exception e){e.printStackTrace ();} "P<IQx
} gnW`|-:\
<=A1d\
D9M<>Xz)
private void processErrorCode(int nErrorCode) #5xK&qA
{ Y '&&1R
System.err.println("Error Code : " + nErrorCode); ~6z<tyD^
} {OP[Rrm
)UA};Fus
*p}b_A}D
//停止文件下载 3~~KtH=
public void siteStop() DIH|6R
{ =7@N'xX
bStop = true; {ZiJnJX
for(int i=0;i<nStartPos.length;i++) bI 3o|
fileSplitterFetch.splitterStop(); :c@v_J6C&
V&U1WV/
Vp*#,(_G:
} i>YD_#w
} fr$E'+l)
//负责部分文件的抓取 }{Ab:+aNd
**FileSplitterFetch.java CM+Nm(|\,
*/ T u>5H`
package NetFox; DT`TA#O
5qzFH,
.}n%gc~A
import java.io.*; 0b%"=J2/p.
import java.net.*; {.=089`{
#~l(t_m{
~Ts^z(v~D2
public class FileSplitterFetch extends Thread { vt@5Hb)
n$RhD93
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String sURL; //File URL n4;
long nStartPos; //File Snippet Start Position '\8gY((7
long nEndPos; //File Snippet End Position k%|7H,7
int nThreadID; //Thread's ID *Y"Kbn6
boolean bDownOver = false; //Downing is over o2
boolean bStop = false; //Stop identical XKD0n^L[
FileAccessI fileAccessI = null; //File Access interface h.PVRAwk
`)Z"||8K
J jRz<T;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f%fD>a
{ `yYoVu*
this.sURL = sURL; U.]5UP:a
this.nStartPos = nStart; -`nQa$N-
this.nEndPos = nEnd; LT7C>b
nThreadID = id; qdkhfm2(K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Bw _^"e8X
} 'B dZN
Z<L|WRe
cPD&xVwq>
public void run() IE7%u92
{ }71a3EUK
while(nStartPos < nEndPos && !bStop) \ng!qN
{ ~9%L)nC2'
\1Tu P}P
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try{ `@%hz%8Y
URL url = new URL(sURL); "Sm'TZx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xNlxi
httpConnection.setRequestProperty("User-Agent","NetFox"); {nvF>
String sProperty = "bytes="+nStartPos+"-"; ctI=|K
httpConnection.setRequestProperty("RANGE",sProperty); \*x'7c/qg
Utility.log(sProperty); rCt8Q&mzf
i\~@2
3@#WYvD
InputStream input = httpConnection.getInputStream(); Er /:iO)_
//logResponseHead(httpConnection); :;Z?2P5i
J @eu]?h
$gZC"~BR
byte[] b = new byte[1024]; qiEw[3Za]'
int nRead; I'6wh+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z:>)5Z{'
{ t}FwS6u
nStartPos += fileAccessI.write(b,0,nRead); n hT%_se4
//if(nThreadID == 1) mhh^kwW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P/%5J3_,
} yN-o?[o
X5[.X()M4
v\&C]W]
Utility.log("Thread " + nThreadID + " is over!"); "[A]tklP
bDownOver = true; ^j~CYzmt
//nPos = fileAccessI.write (b,0,nRead); =CBY_
} MZJ@qIg[Y
catch(Exception e){e.printStackTrace ();} v_U+wga
} i2bkgyzB.
} Xy(8}
)W,tL*9[
m9~cQ!m
//打印回应的头信息 6:\0=k5
public void logResponseHead(HttpURLConnection con) PB[Y^q
{ a-[:RJW
for(int i=1;;i++) ENoGV;WG
{ -/^a2_d[
String header=con.getHeaderFieldKey(i); [f._w~
if(header!=null) 3[_zz;Y*d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HNXMM
Utility.log(header+" : "+con.getHeaderField(header)); LVHIQ9
else <!qN<#$y
break; PMOyZ3
} YCBp]xuE
} {3)^$F=T
!H)Cua)
-_`dA^
public void splitterStop() oItEGJ|
{ <GdQ""X
bStop = true; %Z.!T
} yj<j>JtN
mFk6a{+YX
"UM*(&
} 8PRKSJ[@K
(~k{aO
|$^a"Yd`9
/* BYuoeN!
**FileAccess.java ^RIDC/B=V6
*//文件访问(定位，写) s?Wkh`b
package NetFox; rjaG{ i
import java.io.*; OYYk[r
Zqi;by%
NzBX2
public class FileAccessI implements Serializable{ {zNFp#z
mMt~4(5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q[6<Y,}(pd
RandomAccessFile oSavedFile; 5~!&x@
long nPos; 7my7|s[
UngK9uB~
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public FileAccessI() throws IOException cXDG(.!n7B
{ K?J?]VCw
this("",0); f.e4 C,
} }LA7ku
+$CO
QKP@+E_U
public FileAccessI(String sName,long nPos) throws IOException &YpWfY&V
{ zZE@:P&lf
oSavedFile = new RandomAccessFile(sName,"rw"); 8+|7*Ud
this.nPos = nPos; <&CzM"\Em
oSavedFile.seek(nPos); 26[.te9
} h.t2;O,b
35}]U=
ZHN}:W/p
public synchronized int write(byte[] b,int nStart,int nLen) -~+Y0\%E
{ `mp3ORR;$
int n = -1; Y I?4e7Z+
try{ dN)@/R^E;
oSavedFile.write(b,nStart,nLen); :c/](M
n = nLen; o0B3G
} b%_[\((
catch(IOException e) +Rq7m]
{ "k>;K,:
e.printStackTrace (); X/AA8QV o
} $T2n^yz
`21$e
G5Z_[Q~z
return n; y9::m]s
} gPf^dGi7t
GiS{=+=5
&60#y4
} d{FD.eI0
-egu5#d>
r>kDRIHB
/* ;)rs#T;$
**SiteInfoBean.java g@s'-8}X^
*/ ,/1[(^e
package NetFox; iosL&*'8
:G/.h[\R|
Op 0Qpn
public class SiteInfoBean { 2E/yZ ~2s
P$hmDTn72
o4d[LV4DS
private String sSiteURL; //Site's URL yS"; q
private String sFilePath; //Saved File's Path |)pgUI2O[
private String sFileName; //Saved File's Name "v[?`<53^l
private int nSplitter; //Count of Splited Downloading File -MTO=#5z
Fq`wx
rvwfQ'14
public SiteInfoBean() .4cOMiG
{//nSplitter的缺省值为5 MU#$tXmnC
//default value of nSplitter is 5 \+I+Lrj%
this("","","",5); &h67LMD!
} KOP*\\1 J
EwuBL6kN
eT ZQ[qMp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lKA2~o
{ $@}\T
sSiteURL= sURL; MoP,a9p
sFilePath = sPath; j|c6BdROl
sFileName = sName; M\w%c5
this.nSplitter = nSpiltter; R3!3TJ
&-B&s.,kj
1Zi(5S)
} h_?#.z0ih;
1z5\>F
Yv7`5b{N.
public String getSSiteURL() +`$[h2Z=:
{ otSF8[
return sSiteURL; {S=gXIh(y
} TkjPa};R
1Yb9ILX[J
oHj64fE9
public void setSSiteURL(String value) _>)=c<HL
{ z;KUIWg
sSiteURL = value; j[q$;uSD
} @ZFU< e$!
NX5NE2@^qH
uom~,k$|
public String getSFilePath() /ar/4\b
{ _!'sj=n]q
return sFilePath; _0c$SK
} wG2-,\:
Q{))+'s2h
'h~I#S4!
public void setSFilePath(String value) EHC^ [5
{ #{L !o5
sFilePath = value; R$xkcg2(
} {V*OYYI`R
k w]m7T
eHy.<VX
public String getSFileName() DfL>fk
{ 7IV:X _y
return sFileName; cojbuo
} A_\ZY0Xt
nM,5KHU4a
va_TC!{;
public void setSFileName(String value) !s:v UY58
{ eODprFkt}
sFileName = value; afWEt -
} FeM,$&G:
GOeYw[Vh
`'^&* 7,
public int getNSplitter() {<_9QAS
{ ;"@FLq(n
return nSplitter; I$7TnMug
} =*u:@T=d5
RZ:i60
M+N7JpR
public void setNSplitter(int nCount) b[I;6HW
{ /`Wd+
nSplitter = nCount; |NiWr1&i0
} b@&ydgmaQ
} ^9Je8 @Yu
;%R+]&J
oQvG3(.
/* sa71Vh{
**Utility.java F ;m1I+;
*/ s: .5S
package NetFox; W]v[Xm$q
5_mb+A n,
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public class Utility { 5^\f[}
*<**rY*
EPz$`#Sh"
public Utility() I2!0,1Q
{ ~!,Q<?
g8{?;
?6bk&"T?
} ,cvLvN8
jnK8 [och
//线程睡眠 <h/\)bPB
public static void sleep(int nSecond) ezt_ct/Z
{ I]`>m3SJ
try{ %KeQp W
Thread.sleep(nSecond); G~{xTpL
} \Mv8pU
catch(Exception e) ;n*N9-|.
{ O/IW.t
e.printStackTrace (); qO<'_7TN[
} |f^/((:D
} 27vLI~
3mIX9&/
//日志 sg(L`P
public static void log(String sMsg) H7e/6t<x
{ 6/9h=-w&
System.err.println(sMsg); Musz+<]
} ]u_^~
"Yn<]Pa_
62}bs/%
public static void log(int sMsg) &Z+a (
{ )>ed6A1
System.err.println(sMsg); [|2uu."$
} @NXGVmY1}
} $J#}3;a
\<VwGbzFi
5hE8b {V
/* yKO84cSl
**TestMethod.java /FiFtAbb
*/ q4$R?q:^
package NetFox; UcMe("U
C"/]X
N1I1!!$K;%
public class TestMethod { [Bp[=\
5FHpJlFK,
$2F*p#l(<Z
public TestMethod() =VlO53Hy{
{ ///xx/weblogic60b2_win.exe /|y3M/;F
try{ }[PbA4l.g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Nh41o0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #3$U&|`
SiteFileFetch fileFetch = new SiteFileFetch(bean); E~zLhJTUL'
fileFetch.start(); IPcAE!h6zN
} k6~k
catch(Exception e){e.printStackTrace ();} :&`Yz
c3|;'s
yov:JnWo
} ~Gc+naE>
fPHv|_XM>
sm}v0V.Js
public static void main(String[] args) M6!kn~
{ ~aH*ZA*f
new TestMethod(); 5/mW:G,&
} "HVwm>qEi
} B[-%A!3 F
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