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)); R S] N%`]
} kD6Iz$tr
for(int i=0;i<nEndPos.length-1;i++) 4v2JrC;
{ qJw\<7m
nEndPos = nStartPos[i+1]; 2FGCf} ,
} ?i}wm`
nEndPos[nEndPos.length-1] = nFileLength; *=77|Dba
} m;S%RB^~H
} JC}T*h>Ee
6mjD@
`0-i>>
//启动子线程 5'_:>0}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kqGydGh*"
for(int i=0;i<nStartPos.length;i++) u3sr"w&
{ |V^f}5gd
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K]&GSro
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `R*!GHro
nStartPos,nEndPos,i); jEK{47i v
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); id]}10
fileSplitterFetch.start(); FV%|*JW[;N
} <f0yh"?6VH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z 2lX^z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )2r_EO@3HP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m*v@L4t(1
nEndPos = " + nFileLength); VYrs4IFT$
// fileSplitterFetch[nPos.length-1].start(); A$?o3--#]G
TBgiA}|\D
fqn;,!D?9
//等待子线程结束 g^^^fKUp)
//int count = 0; b)T6%2
//是否结束while循环 ~}Z{hs)
boolean breakWhile = false; B&}lYo
<lWBhrz
~u r}6T
while(!bStop) x_= 3!)
{ A64c,Uv
write_nPos(); h9rrkV9
Utility.sleep(500); ,u14R]
breakWhile = true; uC2 5pH"
+\J+?jOC4S
0- u,AD
for(int i=0;i<nStartPos.length;i++) pWKI^S
{ #?~G\Ux0/
if(!fileSplitterFetch.bDownOver) ,Uy~O(Ft
{ Po.izE!C
breakWhile = false; zhU^~4F
break; g5 y*-t
} ^;@!\Rc
} vQ[ TcV
if(breakWhile) e(9K.3@{
break; e{.P2rnh
xP 3>8Y
SnoEi~Da
//count++; ,;yaYF6|/
//if(count>4) UiZ1$d*
// siteStop(); ?y^ ix+M
} IOl0=+p
f1t?<=3Ek<
!KHbsOT?9
System.err.println("文件下载结束！"); 3GZrVhU?m
} MED_#OS
catch(Exception e){e.printStackTrace ();} a(x#6
} T=fVD8
Vtk}>I@%
Y7`Dx'x
//获得文件长度 _Fjax
public long getFileSize() (KR.dxzjf
{ q&,uJo
int nFileLength = -1; ;$UB@)7%
try{ qx}*L'xB
URL url = new URL(siteInfoBean.getSSiteURL()); oSP^ .BJ$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?q"9ZYX<
httpConnection.setRequestProperty("User-Agent","NetFox"); KzB9 mMrO
bbWW|PtWwP
W}k)5<C4v
int responseCode=httpConnection.getResponseCode(); 1["IT.,f.
if(responseCode>=400) 'he&h4fm
{ x!UGLL]_M
processErrorCode(responseCode); ?)4c!3#
return -2; //-2 represent access is error Q>\9/DjUp
} 0|?DA12Z
&I/C^/F&
i.+#a2
String sHeader; > !WFY
3 FLht L
hy@e(k|S]U
for(int i=1;;i++) > Cx;h=
{ _Tf0L<A'R
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q_:B=w+bC
//Utility.log(in.readLine()); -J++b2R\%
sHeader=httpConnection.getHeaderFieldKey(i); EyV6uk~
if(sHeader!=null) 1(4IcIR5T;
{ ;*e$k7}F
if(sHeader.equals("Content-Length")) I0sw/,J/Z
{ 8FBXdk?A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wQX%*GbL2
break; 0f,Ii_k bT
} <:~'s]`zf
} d'p@[1/
else nAyyjd3!S
break; lUHpGr|U%
} Il!#]
} tEllkHyef
catch(IOException e){e.printStackTrace ();} Q_A?p$%;L
catch(Exception e){e.printStackTrace ();} It8@Cp.dU
<Kq!)) J'
-)E6{
Utility.log(nFileLength); +Z/aG k;
$9<P3J 1
y?V#LW[^E
return nFileLength; RZI4N4o
} (M,*R v
u]t#Vf-$u
o&rNM5:
//保存下载信息（文件指针位置） )n$RHt+:>
private void write_nPos() T28Q(\C:}
{ C?PgC~y)
try{ +p &$`(
output = new DataOutputStream(new FileOutputStream(tmpFile)); $-_@MT~
output.writeInt(nStartPos.length); Ga$EM
for(int i=0;i<nStartPos.length;i++) @ {8xL
{ vce1'aW
// output.writeLong(nPos); 3HB(rTw
output.writeLong(fileSplitterFetch.nStartPos); Ndqhc
output.writeLong(fileSplitterFetch.nEndPos); W$u/tRF
} 3?yq*uE}
output.close(); 6s&%~6J,
} {i:Ayhq~&
catch(IOException e){e.printStackTrace ();} EN~ha:9
catch(Exception e){e.printStackTrace ();} EP]OJ$6I
} l1}HJmom
o%?~9rf]]
M\bea
//读取保存的下载信息（文件指针位置） 8f-B-e?k
private void read_nPos() YN5p@b=FX
{ __,}/|K2
try{ @m ?&7{y#?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -wn(J5NnR
int nCount = input.readInt(); Xq.GvZS`
nStartPos = new long[nCount]; A*+KlhT
nEndPos = new long[nCount]; 8J+:5b_?
for(int i=0;i<nStartPos.length;i++) 9rQw~B<S
{ RyN?Sn5)
nStartPos = input.readLong(); ;NrU|g/ksX
nEndPos = input.readLong(); l|~SVk|
} -hpMd/F
input.close(); 1$rrfg
} 7Dwf0Re`
catch(IOException e){e.printStackTrace ();} oA$]%
catch(Exception e){e.printStackTrace ();} I=wA)Bli1p
} DX@*lM
K7gqF~5x~
vhu5w#]u*
private void processErrorCode(int nErrorCode) :X~{,J
{ )x&OdFX
System.err.println("Error Code : " + nErrorCode); &oqzQ+H
} UNd+MHE74I
/km'#f)/
$eUJd Aetk
//停止文件下载 **lT 'D
public void siteStop() he1W22
{ )w!*6<
bStop = true; FVS@z5A8<=
for(int i=0;i<nStartPos.length;i++) wMru9zyI
fileSplitterFetch.splitterStop(); +G<9|-
dnUiNs8
d(j|8/tpA
} 9mfP9
} ixIfJ
//负责部分文件的抓取 Xu#K<#V
**FileSplitterFetch.java tD !$!\`O
*/ 9x9~u8j
package NetFox; Xw[|$#QKM
+b6kU{
6?(vXPpT$
import java.io.*; MnymV;y"
import java.net.*; 8t Ef>
?g #4&z.
7Yd]#K{$
public class FileSplitterFetch extends Thread { {pW(@4U
q<*UeyE S
\hT=U*dMR
String sURL; //File URL # ~T KC|G
long nStartPos; //File Snippet Start Position Gu P1
long nEndPos; //File Snippet End Position 60&4?<lR4
int nThreadID; //Thread's ID ImVHX~qHJ
boolean bDownOver = false; //Downing is over d 1bx5U
boolean bStop = false; //Stop identical dTW3mF4=
FileAccessI fileAccessI = null; //File Access interface >@NGX-gp
EkEU}2
Rt10:9Kz$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nXnO]wXC
{ vx8-~Oq{|;
this.sURL = sURL; u4p){|x7s
this.nStartPos = nStart; v22ZwP
this.nEndPos = nEnd; iH""dtO
nThreadID = id; BSib/)p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0"to]=
} fA>FU/r
#'jd.'>
KQ(7%W
public void run() 1P+Te,I
{ i VIpe
while(nStartPos < nEndPos && !bStop) b#[7A
{ IHlTp0?
q-)Ynp4'
c-{;P>L
try{ N3}jLl/
URL url = new URL(sURL); P_f^gB7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?h4Rh0rkX
httpConnection.setRequestProperty("User-Agent","NetFox"); 49m}~J=*
String sProperty = "bytes="+nStartPos+"-"; C0@[4a$8f
httpConnection.setRequestProperty("RANGE",sProperty); h16i]V
Utility.log(sProperty); $5n6C7
jvfQG:F }
4S+sz?W2j
InputStream input = httpConnection.getInputStream(); #b?)fqRJL
//logResponseHead(httpConnection); jsrIZbN
RY]Vo8
;_vo2zl1
byte[] b = new byte[1024]; 9:tn!<^=I
int nRead; #fR~7KR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o1(?j}:c|
{ (jY -MF3
nStartPos += fileAccessI.write(b,0,nRead); HQOz
//if(nThreadID == 1) /Sag_[i
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9s}y*Vp
} BCtm05
8S_v} NUm
};=44E'7
Utility.log("Thread " + nThreadID + " is over!"); CnA0^JX
bDownOver = true; )Cm7v@B
//nPos = fileAccessI.write (b,0,nRead); 4Cdl^4(LT
} 2'6:fr=R
catch(Exception e){e.printStackTrace ();} )HN,Az"
} GE{u2<%@
} 56 raZC
TQ\\/e:
~Uz1()ftz
//打印回应的头信息 ,B=;NKo
public void logResponseHead(HttpURLConnection con) sjISVJ?
{ xEfz AJ5&
for(int i=1;;i++) 0=^A{V!m
{ M>BcYbXf
String header=con.getHeaderFieldKey(i); }JKK"d}U
if(header!=null) BCK0fk~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4pfv?!Oj
Utility.log(header+" : "+con.getHeaderField(header)); 5@xl/
else ;%H/^b.c
break; @a{1vT9b
} |tkhsQ-;
} *j0kb"#
g^dPAjPQ
mSu1/?PS
public void splitterStop() *&VqAc%qD
{ iEJY[P1
bStop = true; 3Y}X7-|)Z
} aMaFxEW
*75?%l
(t\ F>A
} n 7Bua
2}^fhMS
yA/b7x-c
/* X-&U-S;
**FileAccess.java "7*cF>FE8
*//文件访问(定位，写) !h "6h
package NetFox; #~SQujgB
import java.io.*; LK'|sO>|
pg.z `k
@+3@Z?!SZ
public class FileAccessI implements Serializable{ ARD&L$AX
^Cs5A0xo#s
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oq<n5
RandomAccessFile oSavedFile; &Jr~)o
long nPos; `2M`;$~ 5
+Xg]@IS-eg
M@n9i@UsO
public FileAccessI() throws IOException AJ*FQo.U
{ AIR\>.~"i*
this("",0); Q'ok%9q!p
} xgi/,Nk '
fA]b'8
'NJCU.lKm
public FileAccessI(String sName,long nPos) throws IOException 5+gSpg]i
{ YRy5.F%?
oSavedFile = new RandomAccessFile(sName,"rw"); $RYsqX\v
this.nPos = nPos; CqRG !J
oSavedFile.seek(nPos); V*m@Rs!)2
} G@O~*k1v
<L1;aNN
0pSqk/
public synchronized int write(byte[] b,int nStart,int nLen) |G5Me
{ %b H1We
int n = -1; m&H@f:
try{ #sOkD
oSavedFile.write(b,nStart,nLen); ItZqLUJm
n = nLen; Fnnk}I}
} 1%?J l~M
catch(IOException e) pD+_ K
{ a/Cd;T2
e.printStackTrace (); .7ZV:m
} k|^e=I
3}@!TI
5,0fL
return n; vj+x(
} z4snH%q
n6PXPc
b`@aiXN)+
} wX_s./#JJ
P+m{hn~%
<23oyMR0
/* &gn^i!%Z)
**SiteInfoBean.java ~f[AEE~,s+
*/ 1Qi5t?{
package NetFox; ,<[Q/:}[
!18M!8Xea
[f'V pId8
public class SiteInfoBean { :<
|z!Y,zaX
3J2j5N:g
private String sSiteURL; //Site's URL j0p'_|)(
private String sFilePath; //Saved File's Path 6iiH+Nc
private String sFileName; //Saved File's Name zqaz1rt[
private int nSplitter; //Count of Splited Downloading File =kp-[7
O<0G\sU
z9k3@\7
public SiteInfoBean() rKR2v(c
{//nSplitter的缺省值为5 !+;'kI2
//default value of nSplitter is 5 X\r?g
this("","","",5); nMK,g>wp
} HMQi:s7%
q1Ja*=r
?h;Zdv>`xz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~bp^Q| wM
{ jpl"KN?X
sSiteURL= sURL; CH6^;.
sFilePath = sPath; fa7I6 i
sFileName = sName; ZgN)sVJ
this.nSplitter = nSpiltter; fZqMznF
nQ*9|v4
E,]G Ek
} 9'tElpDJ6#
;+%(@C51GE
zCvt"!}RRa
public String getSSiteURL() s3+^q
{ .^<4]
return sSiteURL; ]UR@V;JG
} }n+#o!uEf
6]=$c<.&
de?Bn+mvi.
public void setSSiteURL(String value) SH"e x,=
{ cxBu2(Y
sSiteURL = value; Hshm;\'
} tpJe1J<
YQyf:xJ
~kdxJP"
public String getSFilePath() 5]/i[T_
{ bk@F/KqL
return sFilePath; ~bSPtH ]6d
} GA,6G [E
wf4?{H
"XWrd[Df
public void setSFilePath(String value) CNCWxu
{ Cv@ZzILyoK
sFilePath = value; .w/_Om4T*b
} K:!|xr(1d
`'Fz:i
*_ 2db
public String getSFileName() D<=:9
{ nE!h&}(
return sFileName; (nWi9(}J
} A.aUWh
E2M|b
@Sxb}XI!f
public void setSFileName(String value) i%m]<yElm
{ kW"6Gc&HUN
sFileName = value; :Ogt{t
} #&JhA2]q
j[zo~Y4z
#HjiE
public int getNSplitter() Ww9%6 #it
{ &,pL3Qos
return nSplitter; KLpe!8tAe
} Xx~za{p
FOB9J.w4
D$W&6'
public void setNSplitter(int nCount) 26yjQ
{ H1`}3}"
nSplitter = nCount; otQulL)T/
} ;A~efC^<
} Tw|cgB
3<ikMUq&
7B@[`>5?%L
/* N/ 7Q(^
**Utility.java E1(2wJ-3"
*/ KkVFY+/)
package NetFox; N"X;aVFs_
?[n{M
p>w{.hC@
public class Utility { M_-LI4>
BU-m\Kf)
^oNk}:>
public Utility() 0/7y&-/(
{ zJE$sB.f
Bvke@|]kW
F!FXZht$P
} ykY#Y}?^
0'Kbh$LU
//线程睡眠 r;gtfX*
public static void sleep(int nSecond) pBW|d\8
{ .VFa,&5;3
try{ 9>y6zFTV
Thread.sleep(nSecond); 7X\azL
} !&f(Xs
catch(Exception e) vYT%e:8)q
{ Nqih LUv
e.printStackTrace (); E'|@hL-jn
} CAGaZ rx
} .G"UM>.}d
GtQ$`~r
//日志 pkd#SY
public static void log(String sMsg) JI{|8)S
{ mez )G|
System.err.println(sMsg); [ugBVnma
} fmuAX w>
QLx]%E\
s bf\;_!
public static void log(int sMsg) *h=|KOS
{ >Qk4AMIO
System.err.println(sMsg); uWs5+
} >EQd;Af
} @lo6?9oNo
4a'GWzUtS
;t'~
/* 3B }Oy$p
**TestMethod.java ,uEi*s>
*/ +9S_H(
package NetFox; !}u'%
crV2T
{1H3VSYq
public class TestMethod { |Qq_;x]
,j{$SuZM
J|k~e,C
public TestMethod() dW3q
{ ///xx/weblogic60b2_win.exe 1aC?*,e?
try{ zLQplw`#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F<'@T,LVc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ol8ma`}Nq3
SiteFileFetch fileFetch = new SiteFileFetch(bean); j5lSu~
fileFetch.start(); m791w8Vr
} L;a>J
catch(Exception e){e.printStackTrace ();} <"|BuK
~HbZRDcJc
B(<;]
} ekB!d
>P7|-bV
P4vW.|@
public static void main(String[] args) [[{y?-U
{ tx=~bm"*?
new TestMethod(); JFw<Po,MEa
} k_)H$*
} ^rd]qii"
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