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)); oZQ%P
} LlrUJ-uC7
for(int i=0;i<nEndPos.length-1;i++) Xg_M{t
{ f{t5r
nEndPos = nStartPos[i+1]; z~# .Ey
} _2R;@[f2
nEndPos[nEndPos.length-1] = nFileLength; 4'RyD<K\
} GNgPf"}K
} &k+jVymH
BRi\&&<4
0P3^#j
//启动子线程 6X$]d^)h{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Oc}4`?oy<O
for(int i=0;i<nStartPos.length;i++) h2QoBGL5
{ [:&4Tp*C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WA\ P`'lg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5RrzRAxq
nStartPos,nEndPos,i); {r yv7G
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %scSp&X
fileSplitterFetch.start(); }4Ef31X8q
} xKi: 2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q@1b{q#C5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rF'_YYpr>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AvfSR p
nEndPos = " + nFileLength); K-cRNt
// fileSplitterFetch[nPos.length-1].start(); Y`eUWCD
(J I4ibP
h8iic
//等待子线程结束 \fj*.[,
//int count = 0; ANR?An
//是否结束while循环 _a|-_p
boolean breakWhile = false; airg[dK
p6VS<L
]|KOc& y:I
while(!bStop) zy^t95/m
{ ue"?n2
write_nPos(); V+G.TI P
Utility.sleep(500); nd_+g2x'
breakWhile = true; (S3\O `5
HRS^91aK
He @d~9M
for(int i=0;i<nStartPos.length;i++) #&u9z5ywM
{ :08b&myx
if(!fileSplitterFetch.bDownOver) l|TiUjs
{ 6jyS]($q
breakWhile = false; [CTE"@A
break; 2#%@j6
} %#kml{I
} t@m!k+0
if(breakWhile) <Ih)h$8`
break; r{R879
)(V|d$n
.dM4B'OA?
//count++; rWsUWA T*
//if(count>4) %xv }
// siteStop(); j N":9+F
} V9 Z
90<z*j$EK
2%o@?Rp
System.err.println("文件下载结束！"); b/"&E'5-`\
} "V|&s/9
catch(Exception e){e.printStackTrace ();} StZ GKY[Q
} mu`:@7+Yp
P`^3-X/
T)4pLN E
//获得文件长度 CNP!v\D
public long getFileSize() [[ {L#
{ t,H=;U#
int nFileLength = -1; O\0]o!
try{ &q8oalh
URL url = new URL(siteInfoBean.getSSiteURL()); mcO/V-\5'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); drRi<7 i
httpConnection.setRequestProperty("User-Agent","NetFox"); W@S>#3,
pe%$(%@v
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int responseCode=httpConnection.getResponseCode(); '$nm~z,V
if(responseCode>=400) &}}UdJ`
{ fib#)KE
processErrorCode(responseCode); % \N52
return -2; //-2 represent access is error 8);G'7O
} iwM$U( 9
J[0o6
r2!\Ts5v
String sHeader; H 5\k`7R
5=cS5q@
L F<{/c9,
for(int i=1;;i++) vT1StOx<V
{ iG+hj:5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k9Pwf"m|](
//Utility.log(in.readLine()); gs/ i%O
sHeader=httpConnection.getHeaderFieldKey(i); Vd%%lv{v
if(sHeader!=null) ~F; ~
{ dbVMG-z8
if(sHeader.equals("Content-Length")) R"Ff(1m
{ T- ~l2u|s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Pk{eGG<F$
break; E]@$,)nC
} )O}q{4,}
} ,76xa%k(U|
else L'A9TW2
break; -2DvKW$
} +wPXDN#R
} cpLlkR O
catch(IOException e){e.printStackTrace ();} JJE?!Yvc
catch(Exception e){e.printStackTrace ();} <A~a|A-QFR
Dt]N&E#\D
A [c1E[
Utility.log(nFileLength); `PoFKtVXM
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r%=}e++^%
return nFileLength; PoB-:G6
} ,y>Sq +
Z.QgL=
r3;@
//保存下载信息（文件指针位置） :o"9x,
private void write_nPos() mZG)#gW[
{ G>@KX
try{ ;URvZ! {/Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); THN//}d
output.writeInt(nStartPos.length); WWBm*?U
for(int i=0;i<nStartPos.length;i++) NP#6'eH\
{ Q%T[&A}3B
// output.writeLong(nPos); 1U?,}w
output.writeLong(fileSplitterFetch.nStartPos); k.5(d.*(
output.writeLong(fileSplitterFetch.nEndPos); I,8f{T!O@"
} Ez)hArxns
output.close(); Bz+zEXBC
} R"2wop
catch(IOException e){e.printStackTrace ();} U\'HB.P\
catch(Exception e){e.printStackTrace ();} fV(WUN+
} _/c1b>kcso
ko-,l6E
*r90IS}A$2
//读取保存的下载信息（文件指针位置） -ZVCb@%
private void read_nPos() tg~@(IT}j
{ nhdOo
try{ /}kG$~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |d)*,O4s
int nCount = input.readInt(); $S6%a9m
nStartPos = new long[nCount]; d YliC
nEndPos = new long[nCount]; u5Tu~
for(int i=0;i<nStartPos.length;i++) T9'd?nw9
{ jL6ZHEi#d7
nStartPos = input.readLong(); 7{JIHY+
nEndPos = input.readLong(); >}7Ml
} 'qy LQ:6
input.close(); t@vVE{`
} Kg;u.4.-M
catch(IOException e){e.printStackTrace ();} I%<LLkQ
catch(Exception e){e.printStackTrace ();} l^k/Y ]
} iwVsq_[]L
yQz6K6p
;Pw\p^wz
private void processErrorCode(int nErrorCode) $p;<1+!
{ 6"djX47j
System.err.println("Error Code : " + nErrorCode); AY x*Ngn
} P]^BE;7T
}nx5
(~IoRhp^
//停止文件下载 ,L&d\M"f
public void siteStop() [C^&iLX/F*
{ pf8M0,AY
bStop = true; ascY E
for(int i=0;i<nStartPos.length;i++) ^&Vj m
fileSplitterFetch.splitterStop(); Q8Fqf ;4
xg;I::hE7X
wrhGZ=k{
} J\l'nqS"
} 259R5X<V
//负责部分文件的抓取 %y|L'C,ge"
**FileSplitterFetch.java 4Q17vCC*n
*/ =kP|TR!o-
package NetFox; Liv.i;-qE
`UD,ne
w!|jL $5L
import java.io.*; or qL0i
import java.net.*; uA[c$tBe
H3>49;`
zL!}YR@&u"
public class FileSplitterFetch extends Thread { S&J>15oWM`
evvv&$&
s+<`iH9Hm
String sURL; //File URL xOt {Vsv
long nStartPos; //File Snippet Start Position [[7=rn}@<
long nEndPos; //File Snippet End Position 3C gmZ7[
int nThreadID; //Thread's ID ty\F~]Oo
boolean bDownOver = false; //Downing is over OPuty/^!Gw
boolean bStop = false; //Stop identical S;K5JBX0#
FileAccessI fileAccessI = null; //File Access interface <~teD[1k"
_Kwp8_kTr
5ktFL<^5T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]|_UpP8EP
{ =/e$Rp
this.sURL = sURL; +~n4</
this.nStartPos = nStart; :|a$[g5
this.nEndPos = nEnd; cH:9@>'$a
nThreadID = id; Ay@/{RZz
fileAccessI = new FileAccessI(sName,nStartPos);//定位 83!{?EPE
} Tf40lv+{
6an= C_Mb`
6]|-%
public void run() z'&tmje[?
{ z 4qEC
while(nStartPos < nEndPos && !bStop) _;mA(j
{ F*-+5nJ&@
Q2Dh(
_$KEE|9
try{ nrV!<nNBk
URL url = new URL(sURL); "F:V$,mJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Vji:,k=3\
httpConnection.setRequestProperty("User-Agent","NetFox"); |)*9BN
String sProperty = "bytes="+nStartPos+"-"; {,B.OM)J
httpConnection.setRequestProperty("RANGE",sProperty); B:96E&
Utility.log(sProperty); 7{lWg x
: "^/?Sd
kx,3[qe'S
InputStream input = httpConnection.getInputStream(); %v4*$E!f
//logResponseHead(httpConnection); 5t,X;
i`}!<{k
zJ30ZY:
byte[] b = new byte[1024]; \Mzr[dI
int nRead; ?kULR0uL+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W3gHzT?{
{ O>"T*
nStartPos += fileAccessI.write(b,0,nRead); YYhN>d$
//if(nThreadID == 1) _>J`e7j+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F~sUfqiJ'
} t|m=X
WD@v<Wx)
=Eb$rc)
Utility.log("Thread " + nThreadID + " is over!"); ws<pBC,m
bDownOver = true; .*B@1q
//nPos = fileAccessI.write (b,0,nRead); E[Q2ZqhgbP
} wGw<z[:f
catch(Exception e){e.printStackTrace ();} b}&.IJ&40j
} /@64xrvIl=
} VwKfM MI8
MZ?+I~@
TVF:z_M9
//打印回应的头信息 Vn65:" O
public void logResponseHead(HttpURLConnection con) @<3kj R?j
{ twhT6wz"
for(int i=1;;i++) ;+1ooeU
{ wf_ $#.;m
String header=con.getHeaderFieldKey(i); >Cam6LJ
if(header!=null) 5<M$ XT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #&b<D2d
Utility.log(header+" : "+con.getHeaderField(header)); 3^iVDbAW{
else XAN.Plk
break; {:#c1d2@8
} N;a'`l
} WfHa
nlZJ}xZ
1)3'Y2N*
public void splitterStop() Wuk!\<T{
{ $Wu|4]o>9
bStop = true; L2c\i
} g'td(i[
D&x.io
L|nFN}da
} y@SI)&D
klMpiy
KGGnypx`
/* 6tGF
**FileAccess.java yg6o#;
*//文件访问(定位，写) wq|7sk{
package NetFox; &dPI<HlM
import java.io.*; N8DouDq
Y$#6%`*#>n
ktkS$
public class FileAccessI implements Serializable{ 3:)_oHq
%)Z,?DzZ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Res4;C
RandomAccessFile oSavedFile; Tz~a. h@
long nPos; 6E2#VT>@/
|h\A5_0_
T oT('
public FileAccessI() throws IOException jZH4]^De
{ uqD|j:~ =k
this("",0); s@E)=;!
} nvA7eTO6C
L F&!od9[
E:-~SH}
public FileAccessI(String sName,long nPos) throws IOException S|T_<FCY
{ f&txg,W,yv
oSavedFile = new RandomAccessFile(sName,"rw"); 96S$Y~G#&
this.nPos = nPos; !K+hXQE1
oSavedFile.seek(nPos); 1h#/8X
} u08j9) ,4
RY3=UeoF
+~|Jn_:A f
public synchronized int write(byte[] b,int nStart,int nLen) G.$KP
{ fQ1Dp
int n = -1; I Bko"|e@
try{ #M<YNuE#"
oSavedFile.write(b,nStart,nLen); F'"-aB ~
n = nLen; S;u.Ds&
} 49HP2E
catch(IOException e) qL <@PC.5
{ vY"I
e.printStackTrace (); o2;Eti
} i'10qWz
0~P]Fw^w
;mg.} fI
return n; .V\~#Ro$G
} hi4-Z=pl
&M tF
[mj=m?j
} cB_9@0r[S
J@QOF+&
DliDBArxZ
/* aHb&+/HZ
**SiteInfoBean.java IwOL1\'T4
*/ (N/-blto
package NetFox; x iz+R9p
p&#ju*i6z
-8vGvI>
public class SiteInfoBean { Y;iI=U
] _W'-B
s Ytn'&$\
private String sSiteURL; //Site's URL 4>2\{0r
private String sFilePath; //Saved File's Path O9m sPb:
private String sFileName; //Saved File's Name zo("v*d*q
private int nSplitter; //Count of Splited Downloading File I[b{*g2Zw
F/,6Jh
"kC6G%
public SiteInfoBean() wp'[AR}
{//nSplitter的缺省值为5 lHPnAaue@
//default value of nSplitter is 5 yE.st9m
this("","","",5); nf[KD,f
} =T#hd7O`V
K4H27SH
,1cpV|mAr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s];0-65)
{ _00}O+GLM4
sSiteURL= sURL; [mNum3e
sFilePath = sPath; !vVW8hbp
sFileName = sName; IWm@pfC+g
this.nSplitter = nSpiltter; h~qv_)F_
[w-Tf&
\}%_FnP0ZU
} I2pE}6q
LE~vSm^#
J`C 2}$ ~
public String getSSiteURL() 4F6I7lu
{ ~C3J-z<
return sSiteURL; tOte[~,
} |eg8F$WU
xi4b;U j
W$Xr:RU
public void setSSiteURL(String value) PW iuM=E
{ .:4*HB
sSiteURL = value; I+ 3qu=
} 6xY6EC
}eI9me@Aa
@P>>:002/
public String getSFilePath() 8G2QI4
{ B5h)F> &G
return sFilePath; `sy_'`i>X
} 8zcSh/
f`K#=_Kq7
`:R9M+ OX
public void setSFilePath(String value) ,_/\pX0
{ O2yD{i#l*#
sFilePath = value; IP-M)_I
} NPFI^Uj#A
NH:Bdl3
9i lJ
public String getSFileName() 8e ?9:VM]
{ +2k{yl
return sFileName; \zBZ$5 rE
} !KT.p2\
#;lEx'lKN
T+t7/PwC;
public void setSFileName(String value) W5e>Z&&
{ qsN_EMgbdn
sFileName = value; .W$9nbly
} :Ig9n:
YHke^Ind
(CtRU
public int getNSplitter() *b!.9pK
{ 6 {F#_.
return nSplitter; F&^&"(H}
} 1{RA\CF
%KN2iNq
%Wm)
public void setNSplitter(int nCount) (Rp5g}b
{ j9w{=( MV
nSplitter = nCount; +W$uHQq
} -UAMHd}4
} <Wj/A/
~BgYD)ov
Uqx@9z(
/* oK<H/76x
**Utility.java tNOOaj9mw
*/ [#SO}'1n
package NetFox; [9}<N2,9z
,J<+Wxz
w@YPG{"j
public class Utility { Q,tjODc6n
/QCg E~
aI}htb{m`
public Utility() 4x=sJ%E
{ ^5>W`vwp
uINEq{yo
8/y8tMm]
} J-azBi
mi5bk>o
//线程睡眠 u*oP:!s
public static void sleep(int nSecond) EG_P^<z
{ KV'3\`v@LY
try{ .m%5Esx
Thread.sleep(nSecond); hYA1N&yz@
} c=a;<,Rzb
catch(Exception e) : Q2=t!
{ %kH,Rl\g
e.printStackTrace (); X'%BS
} hY *^rY'
} Nr"GxezU+A
0C"2?etMx
//日志 7|[Dr@.S
public static void log(String sMsg) . S;o#Zw*R
{ t:,lz8Y~
System.err.println(sMsg); C.H(aX)7
} *+2BZZwT
W'E3_dj+
BvHI}=
public static void log(int sMsg) -- IewW
{ CPY|rV
System.err.println(sMsg); W>,D$
} 2$2@?]|?
} 31%3&B:Ts
l Dwq[ I]w
9\E];~"iP
/* *$JS}Pax
**TestMethod.java Q&PEO%/D
*/ ;Yg/y
package NetFox; m1tc="j
hu}uc&N)iE
&t'P>6)
public class TestMethod { @00&J~D
j.V7`x
5l(@p7_+
public TestMethod() 7E?60^Tve
{ ///xx/weblogic60b2_win.exe goD#2lg
try{ o?3C-A|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cA]PZ*]{BN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5twG2p8
SiteFileFetch fileFetch = new SiteFileFetch(bean); dWo$5Bls<A
fileFetch.start(); f,3K;S-he:
} 83'rQDo)G
catch(Exception e){e.printStackTrace ();} >=1UhHFNI
Q(Pc
k>E/)9%ep2
} P8ns @VV
n2["Ln mO
Np.<&`p!
public static void main(String[] args) THy
{ YPw=iF]
new TestMethod(); nA=E|$1
} v|jwz.jM
} 9om}j
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