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)); pl}nbY
} C]EkVcKFA
for(int i=0;i<nEndPos.length-1;i++) o|kiwr}Y
{ {'8td^JEE
nEndPos = nStartPos[i+1]; o%yfR.M6$
} /PZx['g
nEndPos[nEndPos.length-1] = nFileLength; Zh
} t]IHQ8
} dl]pdg<
Y5{KtW
&x9>8~
//启动子线程 fV#,<JG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O*7vmPy
for(int i=0;i<nStartPos.length;i++) 'kOkwGf!
{ \OJam<hZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a`e'HQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6o0}7T%6
nStartPos,nEndPos,i); FMOO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H@xHkqan
fileSplitterFetch.start(); 6& (bL<8b
} dAWB.#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KS'n$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;FGS(.mjlC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^GpLl
nEndPos = " + nFileLength); de/oK c
// fileSplitterFetch[nPos.length-1].start(); DaS~bweMw
mv,5Q6!
29AE B
//等待子线程结束 2$OV`qy@?
//int count = 0; tzShds
//是否结束while循环 ^sKdN-{
boolean breakWhile = false; t[r6jo7
Sa[?B
qRSoF04!R
while(!bStop) N~uc%wOA
{ S zNZY&8 f
write_nPos(); Bs`mzA54
Utility.sleep(500); htT9Hrx
breakWhile = true; {'Y()p3kl
;`O9YbP#
\G#_z|'dN
for(int i=0;i<nStartPos.length;i++) 5X>K#N
{ %[, R Q">v
if(!fileSplitterFetch.bDownOver) =8vNOvA
{ ^g|j4N
breakWhile = false; ;hPVe_/
break; %iB,hGatE
} %+htA0aX
} GorEHlvVh
if(breakWhile) v#lrF\G5
break; ZZw2m@T>
6FYL},.R
&OlX CxH
//count++; =xQPg0g
//if(count>4) v%r/PHw
// siteStop(); O{7rIy
} 7}I';>QH
6j8\3H~
8BrC@L2E0
System.err.println("文件下载结束！"); GEvx<:
} 1s~rWnhVv
catch(Exception e){e.printStackTrace ();} u/<ZGW(&s(
} &xt[w>/i
w~_ycY.e
2 OV$M~
//获得文件长度 * V7bALY
public long getFileSize() ^&\pY
{ qnHjwMi
int nFileLength = -1; ]- 6q`'?[
try{ ce;$)Ff\
URL url = new URL(siteInfoBean.getSSiteURL()); ^OV!Q\j.q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d~MY z6"
httpConnection.setRequestProperty("User-Agent","NetFox"); ] g<$f#S
dU*$V7
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int responseCode=httpConnection.getResponseCode(); :_<&LO]Q
if(responseCode>=400) H | C3{9
{ 3dz{"hV
processErrorCode(responseCode); A;5_/ 2
return -2; //-2 represent access is error Hs$HeAp;
} n*ROlCxV
_u""v
{sxdDl
String sHeader; 6ddRFpe
bo/<3gR
o~9sO=-O
for(int i=1;;i++) 7IFZK\V
{ wpp!H<')
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y}xM&%
//Utility.log(in.readLine()); 7NT0]j(w-
sHeader=httpConnection.getHeaderFieldKey(i); \[qxOZ{
if(sHeader!=null) %y\5L#T!>
{ uF|Up]Z G
if(sHeader.equals("Content-Length")) AFM+`{Cq
{ "uP*pR^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !VaC=I^{
break; !4!qHJISa
} mZXtHFMu
} 1ni72iz\
else urE7ZKdI
break; H5#]MOAP
} t*; KxQ+'?
} am!ssF5s
catch(IOException e){e.printStackTrace ();} 2D:,(
catch(Exception e){e.printStackTrace ();} daP_Kz/2K
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`\|@w@f|;
Utility.log(nFileLength); S>b 3_D
|QF_E4ISD
q"@#FS
return nFileLength; }A]eC
} R!%HQA1U
6&5D4 V
*iY:R
//保存下载信息（文件指针位置） 8(&6*-7=
private void write_nPos() yY!)2{F+
{ j!kJ@lbP
try{ zR'EQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); }ng?Ar[
output.writeInt(nStartPos.length); T`pDjT
for(int i=0;i<nStartPos.length;i++) `&.qHw)
{ ?-%(K^y4r
// output.writeLong(nPos); [E%g3>/mt
output.writeLong(fileSplitterFetch.nStartPos); .I EHjy\+
output.writeLong(fileSplitterFetch.nEndPos); ji>LBbnHdE
} rW|%eT*/'A
output.close(); glc<(V
} ?{}P#sn
catch(IOException e){e.printStackTrace ();} ,\X! :y~
catch(Exception e){e.printStackTrace ();} 2z"<m2a
} q5S_B]|
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mR1b.$
//读取保存的下载信息（文件指针位置） )A%* l9\nG
private void read_nPos() IiRQ-,t1
{ y$bY 8L
try{ $T#fCx/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *U6+b
int nCount = input.readInt(); ;du},>T$n
nStartPos = new long[nCount]; /\<x8BJ
nEndPos = new long[nCount]; F-b]>3r
for(int i=0;i<nStartPos.length;i++) 'K02T:\iZ
{ l`l6Y>c*]
nStartPos = input.readLong(); ^fe,A=k~1
nEndPos = input.readLong(); _68vSYr
} XkkzY5rxOc
input.close(); i].E1},%
} TmftEw>u
catch(IOException e){e.printStackTrace ();} z;P#
catch(Exception e){e.printStackTrace ();} J)yg<*/3
} 2}XRqa.|
v0!|TI3s
[ `1`E1X
private void processErrorCode(int nErrorCode) }aVzr}!
{ lwgwdB
System.err.println("Error Code : " + nErrorCode); Y'm;xA
} ]\ !ka/%
/*>}y$
P_0[spmFU
//停止文件下载 9xj }<WM
public void siteStop() g 8uq6U
{ =n,1*
bStop = true; szhSI
for(int i=0;i<nStartPos.length;i++) ^`iz%^
fileSplitterFetch.splitterStop(); R4VX*qkB
5@r6'Z
u-y?i`
} K> 4w
} +ctU7 rVy
//负责部分文件的抓取 ) 3"!Q+
**FileSplitterFetch.java X<.l(9$
*/ $0K@=7ms
package NetFox; VD@$y^!H
<uS/8MP{
3Mm_xYDud
import java.io.*; 0SWqC@AR%
import java.net.*; W|Sab$h
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2Sa{=x N)
public class FileSplitterFetch extends Thread { `JDZR:bMaT
Kr'?h'F
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String sURL; //File URL Yq51+\d
long nStartPos; //File Snippet Start Position IO9|o!&>
long nEndPos; //File Snippet End Position YLTg(*
int nThreadID; //Thread's ID T%&vq6
boolean bDownOver = false; //Downing is over H"^9g3U
boolean bStop = false; //Stop identical f OR9N/
FileAccessI fileAccessI = null; //File Access interface u&c%L0)E&
Y$"m*0
xRgdU+,Mj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I<sUB4T>#W
{ ;92xSe"Ww
this.sURL = sURL; fap]`P~#L
this.nStartPos = nStart; IAGY-+8e
this.nEndPos = nEnd; F)X`CG ;t
nThreadID = id; Hcg7u7M{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 S'qT+pP
} G1e_pszD{o
/ [49iIzC
'dh{q`#0
public void run() w9<'0wcs
{ J^7M0A4K
while(nStartPos < nEndPos && !bStop) ~!2fUewEu
{ ;SjNZi)4d
0iZeU:FE
,G46i)E\
try{ aXqig&:
URL url = new URL(sURL); ebJTrh<{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'Ca;gi !U
httpConnection.setRequestProperty("User-Agent","NetFox"); ;b=diZE
String sProperty = "bytes="+nStartPos+"-"; R= mTJ'y
httpConnection.setRequestProperty("RANGE",sProperty); @$^4Av-
Utility.log(sProperty); $.$nv~f
- A@<zqu
GVlT+Rs7
InputStream input = httpConnection.getInputStream(); :ChXzZ
//logResponseHead(httpConnection); Q>+rjN;
k'|yUJ,
k)Lhzr[
byte[] b = new byte[1024]; 1;c>#20
int nRead; \xggIW.^0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |;~2y>E
{ LXxQI(RO
nStartPos += fileAccessI.write(b,0,nRead); U`EOun,
//if(nThreadID == 1) dL+yd0b*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZAy/u@qt
} \db=]L=|
%5zIh[!1$
@w.DN)GPo
Utility.log("Thread " + nThreadID + " is over!"); L>1y[ Q
bDownOver = true; wGT>Xh!
//nPos = fileAccessI.write (b,0,nRead); 5vR])T/S0
} z&9MkbH1
catch(Exception e){e.printStackTrace ();} O.QR1
} gy,)%{,G
} X\H P{$fY_
Rzsu 7w
f1'X<VA
//打印回应的头信息 C@:X9NU
public void logResponseHead(HttpURLConnection con) FGP^rTP)e
{ /ivVqOo
for(int i=1;;i++) Yl'8" \HF
{ Dzu//_u
String header=con.getHeaderFieldKey(i); BH~zeJ*Pr
if(header!=null) r0[<[jEh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8N"WKBj|_d
Utility.log(header+" : "+con.getHeaderField(header)); \MmOI<Hd-
else eHs38X
break; x"C7NW[$
} R+K|K2"
} S&IW]ffK
Wp:vz']V
11#b%dT
public void splitterStop() Ut'T!RD
{ :/5GHfyj
bStop = true; 3V^5 4_
} /({oN1X>i
@XtrC|dkkE
_{#K
} M6Xzyt|
6QT&{|q=
}ff^^7_
/* >jmHe^rH
**FileAccess.java LVdR,'lS
*//文件访问(定位，写) mejNa(D ^
package NetFox; ~4FzA,,
import java.io.*; wL:7G
m='}t \=
`<v$+mG
public class FileAccessI implements Serializable{ %vZHHBylu
d(V4;8a0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <N~9=g3
RandomAccessFile oSavedFile; L?|}!
long nPos; (j@c946z""
1fIx@
O9?.J,,mVh
public FileAccessI() throws IOException )hQ]>o@i{
{ #*y.C[^5{
this("",0); YCb|eS^u
} Z]DZ:dF
#7'k'(
~&ns?z>x
public FileAccessI(String sName,long nPos) throws IOException D{\o*\TN
{ |X XO0
oSavedFile = new RandomAccessFile(sName,"rw"); }xBO;
this.nPos = nPos; R(&3})VOa
oSavedFile.seek(nPos); _fY9u2Y
} XMZ$AeF@
*! :j$n;
$*N(feAs
public synchronized int write(byte[] b,int nStart,int nLen) a;IOL
{ NV(jp'i~
int n = -1; t$t'{*t( T
try{ ND.(N'/O
oSavedFile.write(b,nStart,nLen); Rsq EAdZw[
n = nLen; kjsj~jwvv
} - (((y)!
catch(IOException e) ~Yl.(R
{ TTa3DbFp%
e.printStackTrace (); Rm)hgmZ
} /!t:MK;
DxN\ H"
cc`u{F9
return n; /&47qU4PJ
} +IbV
4B[pQlg
+eH`mI0f
} n<FUaR>q}
ZQ`4'|"
V6c8o2G;+
/* ) ] Ro
**SiteInfoBean.java h~qvd--p0
*/ (7!pc
package NetFox; toD!RE
;3& wO~lW
>}NnzZ
public class SiteInfoBean { N+ ]O#Js?
@Z#h?:
H$^9#{
private String sSiteURL; //Site's URL SD%3B!cpX
private String sFilePath; //Saved File's Path Fz<1xyc(
private String sFileName; //Saved File's Name .9z}S=ZK
private int nSplitter; //Count of Splited Downloading File 1~E4]Ef:W
@mg5vt!$`
2g5 4<G*e
public SiteInfoBean() V,c^Vqy
{//nSplitter的缺省值为5 '?.']U,: $
//default value of nSplitter is 5 Ho(}_Q&
this("","","",5); I H#CaD
} *>[q*SF
Z<AZO ^
bYem0hzOe
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @C[p?ak
{ k^;/@:
sSiteURL= sURL; d^tY?*n
sFilePath = sPath; W]bytsl
sFileName = sName; AEWrrE
this.nSplitter = nSpiltter; D(|+z-}M
e8:O2!HW
@44*<!da
} jG& 8`*|*
P<[) qq@;
@~7au9.V=X
public String getSSiteURL() =2rdbq6R
{ @Ss W
return sSiteURL; v;?W|kJ.u
} uhaHY`w
Ywt9^M|z;
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public void setSSiteURL(String value) G#NbLj`h
{ v5?)J91
sSiteURL = value; 8 ks\-38n1
} !~7lY]_U
&"A:_5AU
zd$iDi($
public String getSFilePath() In:V.'D/>t
{ 0%HAa|L,,
return sFilePath; KC9VQeSc
} f0%'4t
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d0%Wz5Np
public void setSFilePath(String value) 4~oRcO8!Y
{ =1!.g"0
sFilePath = value; wM;=^br
} gwB0/$!4"
1_9Ka V
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public String getSFileName() 5=9Eb
{ >OjK0jiPf
return sFileName; ]JmE(Y1(1
} I`g&>
Q=[ IO,f
G'wW-|
public void setSFileName(String value) AhjCRYk+
{ g.8^ )u
sFileName = value; =mcQe^M
} n >E1\($
*N{k#d/
u!It';j
public int getNSplitter() Sc}Rs
{ x|^p9m"=%
return nSplitter; YReI|{O$c
} ?TW?2+
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uz3 ?c6b
public void setNSplitter(int nCount) , :KJ({wM
{ QGErQ +l
nSplitter = nCount; |vG?H#y
} ehe#"exCB
} n1R{[\ >1
S&cN+r
5yV>-XT+-
/* mQU t 'j4
**Utility.java .]<iRf[\[
*/ Gcxz$.(
package NetFox; M#8_Qbvfk
=&.9z 4A
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public class Utility { I>-1kFma;
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pf yJL?_%
public Utility() 81I9xqvSd~
{ hHOx ]
*'{9(Oj
aqi]5,
} 3_i29ghv
&wkbr2P
//线程睡眠 k#V\O2lb
public static void sleep(int nSecond) n7n-uc
{ n{m[ j+UG
try{ jEP'jib%
Thread.sleep(nSecond); =6fJUy^M\
} H:z<]Rc
catch(Exception e) }C=+Tn
{ :2A-;P4
e.printStackTrace (); a`C2:Z23(#
} nx{X^oc8e
} rC/z8m3z
)U}`x }:,
//日志 bQ0+Y?,+/
public static void log(String sMsg) 8KdcU[w]
{ ;__k*<+{.
System.err.println(sMsg); k&u5`F
} k$7Kz"
Ycxv=Et
<fgf L9-
public static void log(int sMsg) J/Ch /Sa
{ |NFDrm
System.err.println(sMsg); 7<?Aou
} zrC1/%T
} hb)83mH}
[cfXcl
q((%sWp
/* X:(t,g*7
**TestMethod.java iE ,"YCK
*/ P}!pmg6V
package NetFox; /(}YjeS
^'b\OUty-
g- INhzMu
public class TestMethod { rPifiLl A>
R!x /,6,_
]<_v;Q<t
public TestMethod() s|:j~>53
{ ///xx/weblogic60b2_win.exe bWZzb&
try{ Cv`dK=n>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9A\\2Zz6F
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); AC?a:{./
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]==S?_.B3n
fileFetch.start(); O&dh<
} W#x~x|(c
catch(Exception e){e.printStackTrace ();} ?,eq86-M
,!^;<UR:
ZYTBc#f
} 7;sF0oB5e
^|cax|>
^/$U(4
public static void main(String[] args) 2(9~G|C.
{ 07,&weQ
new TestMethod(); 4(8BWP~.y2
} O<?.iF%
} 7VfPS5se
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