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)); ;/'|WLI9
} =Vb~s+YW
for(int i=0;i<nEndPos.length-1;i++) , T\-;7
{ &>(gt<C$
nEndPos = nStartPos[i+1]; 5 y
} \"x>JW4w
nEndPos[nEndPos.length-1] = nFileLength; :)IV!_>'d
} cy|%sf`
} KE.Dt
NZk&JND
?x3Jv<G0*
//启动子线程 :.uk$jx
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |]W2EV ,b
for(int i=0;i<nStartPos.length;i++) #?Mj$ZB
{ \a))
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uZIJoT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _BS 9GB
nStartPos,nEndPos,i); 7,'kpyCj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?NG=8.p
fileSplitterFetch.start(); Jdj?I'XtY
} |QMA@Mx
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +Ok%e.\ZM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5~+XZA#2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bik*ZC?E
nEndPos = " + nFileLength); *1^$.Q&
// fileSplitterFetch[nPos.length-1].start(); -M4p\6)Ge
>72JV;W]
30Drrno7Io
//等待子线程结束 r:&|vP
//int count = 0; xAhxD|4_
//是否结束while循环 pQWHG#?7
boolean breakWhile = false; 8TWTbQ
CQ^3v09N;~
Qi9-z'
while(!bStop) E0l_--
{ \+nGOvM
write_nPos(); qZk:mlYd
Utility.sleep(500); A\$ >>Z
breakWhile = true; Z4hLdHo_
B4g8 ~f
Br5o7(AE
for(int i=0;i<nStartPos.length;i++) 4w$_]ke
{ (\,BxvhG=
if(!fileSplitterFetch.bDownOver) osHCg
{ }Hcx=}j
breakWhile = false; ^6;V}2>v}
break; 3l4NC03I&
} @T:faJ5\'
} B_^]C9C|
if(breakWhile) bw4oLu?
break; #=,imsW)
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nFM@@oA
//count++; 2oVV'9;B
//if(count>4) DN8}glVxV
// siteStop(); ~i0R^qfr
} SJ?)%[(T
#VGjCEeU
sZhMa>
System.err.println("文件下载结束！"); ^3]UZ@
} @;Opx."
catch(Exception e){e.printStackTrace ();} 9YN?
} e8P-k3a"5:
K#mOSY;}
\7v)iG|#G&
//获得文件长度 Q2|p\rO
public long getFileSize() _\8qwDg"#e
{ Pbu{'y3J
int nFileLength = -1; v?:: |{
try{ kH948<fk3
URL url = new URL(siteInfoBean.getSSiteURL()); [xZU!=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )R2XU
httpConnection.setRequestProperty("User-Agent","NetFox"); $V>yXhTh
r[txlQI9
ZKpvDH'
int responseCode=httpConnection.getResponseCode(); #{J,kcxS
if(responseCode>=400) 5|8^9Oe5
{ sLL7]m}
processErrorCode(responseCode); If-_?wZe
return -2; //-2 represent access is error T7*wS#z)h
} 0CExY9@Wq
,*svtw:2')
w#y0atsg'
String sHeader; mpw~hW0-
ZWUP^V
3gZ8.8q3
for(int i=1;;i++) 3_$w|ET
{ jXg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); An`3Ex[
//Utility.log(in.readLine()); IE2"rQT
sHeader=httpConnection.getHeaderFieldKey(i); .)tSg
if(sHeader!=null) XMIbUbUk-
{ ~Bi_7 Q
if(sHeader.equals("Content-Length")) XGrue6ya
{ `#P$ ]:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S>Yj@L
break; S$q=;"
} 'tgKe!-@
} hqvE!Of
else Guw}=l--YR
break; )cJ#-M2
} }_'IE1bA
} W_|0y4QOo
catch(IOException e){e.printStackTrace ();} 0%Ll
catch(Exception e){e.printStackTrace ();} fxcc<h4
}T2xXbU
D;}xr_
Utility.log(nFileLength); pKUP2m`MW
K5>p89mZ
tRb]7 z
return nFileLength; 1{x.xi"A/
} SLL3v,P(7
/1UOT\8U
\Q?ip&R
//保存下载信息（文件指针位置） 'dG%oDHX]P
private void write_nPos() ]}="m2S3
{ `r"+644
try{ JuR"J1MY
output = new DataOutputStream(new FileOutputStream(tmpFile)); o G*5f
output.writeInt(nStartPos.length); G3P&{.v
for(int i=0;i<nStartPos.length;i++) 6fo3:P*O
{ K)tQ]P
// output.writeLong(nPos); "p&Y^]
output.writeLong(fileSplitterFetch.nStartPos); CqMhk
output.writeLong(fileSplitterFetch.nEndPos); Cwa^"r3P1
} (& "su3z
output.close(); yF}OfK?0f
} ?t&kb7
catch(IOException e){e.printStackTrace ();} BXms;[
catch(Exception e){e.printStackTrace ();} tc;'oMUP
} Qj{8?lew
|~`as(@Ih
+d}E&=p_
//读取保存的下载信息（文件指针位置） kl!wVLE
private void read_nPos() p@!nYPr.
{ Z%zj";C G
try{ $ i)bq6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^ 2GHe<Y
int nCount = input.readInt(); 2,2Z`X
nStartPos = new long[nCount]; "xI"
nEndPos = new long[nCount]; aimarU
for(int i=0;i<nStartPos.length;i++) 6k{2 +P
{ ,_aM`%q?Fj
nStartPos = input.readLong(); <P[T!gST
nEndPos = input.readLong(); bK"SKV
} i$G;f^Z!Y
input.close(); ( 9!k#
} H`bSYjgM!
catch(IOException e){e.printStackTrace ();} K%<j=c
catch(Exception e){e.printStackTrace ();} g6@Fp7T
} c .3ZXqpI;
,u }XWV
^H{R+}
private void processErrorCode(int nErrorCode) (/!r(#K0,'
{ #4MBoN(3
System.err.println("Error Code : " + nErrorCode); <9E0iz+j
} ptatzp]c#
5Wyz=+?m|
qf@q]wtar
//停止文件下载 8KB>6[H!wE
public void siteStop() sQ6}\
{ <~}7Mxn%x@
bStop = true; M#"524Nz
for(int i=0;i<nStartPos.length;i++) ~vmdXR`'T
fileSplitterFetch.splitterStop(); 7Dzuii?1
!-2R;yo12
'j^xbikr
} ]V %.I_
} D0k 8^
//负责部分文件的抓取 e0@6Pd
**FileSplitterFetch.java n55Pv3}C
*/ v(*C%.M)
package NetFox; h~&gIub
UDhG :
=9oPowq
import java.io.*; I}e3zf>
import java.net.*; i|w8.}0
Wcb7 ;~K
]2#
public class FileSplitterFetch extends Thread { bfB\h*XO
'1,,)U#6E
5w%_$x
String sURL; //File URL =U8a ?0
long nStartPos; //File Snippet Start Position {Q+gZcu
long nEndPos; //File Snippet End Position )1N 54FNO
int nThreadID; //Thread's ID ul%h@=n
boolean bDownOver = false; //Downing is over ZX ?yL>4
boolean bStop = false; //Stop identical D3|oOOoG
FileAccessI fileAccessI = null; //File Access interface QM3,'?ekRH
f|^dD`
5MFxo63
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,jXM3?>B
{ O^/Maa/D1
this.sURL = sURL; FMkOo2{
this.nStartPos = nStart; >fH=DOz$&
this.nEndPos = nEnd; D:k3" E"S
nThreadID = id; `D9]*c !mO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :4~g;2oag
} ^TMJ8`e
`_b`kzJ
hN['7:bQ
public void run() 3qY K_M^[
{ 5H=ko8fZ=
while(nStartPos < nEndPos && !bStop) ~/mwx8~
{ T+N|R
[M.f-x:
k>t)g-,2
try{ "ZTTg>r
URL url = new URL(sURL); | 8qBm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bSVlk`
httpConnection.setRequestProperty("User-Agent","NetFox"); :2njp%
String sProperty = "bytes="+nStartPos+"-"; e]jH+IR:>
httpConnection.setRequestProperty("RANGE",sProperty); Bo<>e~6P
Utility.log(sProperty); R!l:O=[<
u:aW 8
TCT57P#b
InputStream input = httpConnection.getInputStream(); I^oE4o
//logResponseHead(httpConnection); d Le-nF
dt~YW
#gm)dRKm%
byte[] b = new byte[1024]; yLsz8j-QJ
int nRead; piU/&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) A'G@uD@3
{ \rVQQ|l
nStartPos += fileAccessI.write(b,0,nRead); %0? M?Jf
//if(nThreadID == 1) DE2a5+^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F:6SPY y
} w.&1%X(k
"5eNLqt^q
q>w)"Dd
Utility.log("Thread " + nThreadID + " is over!"); cBo{/Tn:
bDownOver = true; }K8/-d6
//nPos = fileAccessI.write (b,0,nRead); wvrrMGU)a
} 7\ nf:.
catch(Exception e){e.printStackTrace ();} 9CCkqB/
} )5|I_PXB
} ='TE,et@d
6sa"O89
~G27;Npy
//打印回应的头信息 8foJI^3
public void logResponseHead(HttpURLConnection con) YC_1Ks
{ &Wf3~hmo
for(int i=1;;i++) >5Wlc$bc
{ SZJ$w-<z
String header=con.getHeaderFieldKey(i); z<.?x%4O
if(header!=null) iS5W>1]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G;f/Tch
Utility.log(header+" : "+con.getHeaderField(header)); N{-]F|XX
else z5W@`=D
break; <cA/<3k)
} J)mhu}
} %F kMv
v\`9;QV5
p-+K4
public void splitterStop() 8EVgoJ.
{ BL 3gKx.'
bStop = true; zD3mX<sw
} 9<Kj6t_
3pmWDG6L
)"+(butI&
} P;pl,~
2< hAa9y
3BpZX`l*p
/* D~o$GW%
**FileAccess.java N41R
*//文件访问(定位，写) <L&m4O#|
package NetFox; y<b{Ji e
import java.io.*; ^Q&u0;OJ
"TH6o:x
^!q?vo\j|
public class FileAccessI implements Serializable{ $<ld3[l i
fvb=#58N_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c*UvYzDZL
RandomAccessFile oSavedFile; 0j C3fT!n
long nPos; Qv-@Zt!8
/*|oL#hK
Kt0(gQOr0
public FileAccessI() throws IOException GJqE!I,.
{ *6(kbes
this("",0); `gKf#f
} .k[o$z\EkF
x1 1U@jd+1
sZ?mP;Q
public FileAccessI(String sName,long nPos) throws IOException @,XSs
{ 2 1PFR:lP7
oSavedFile = new RandomAccessFile(sName,"rw"); ![f ![l
this.nPos = nPos; /t-fjB{=G
oSavedFile.seek(nPos); vd6l7"0/
} vf4{$Oag
Q]o C47(
ItVugI(^ C
public synchronized int write(byte[] b,int nStart,int nLen) /pp1~r.s?>
{ .G o{1[
int n = -1; F7")]q3I~
try{ ;O<9|?
oSavedFile.write(b,nStart,nLen); ?JxbSK#
n = nLen; "`[!Lz
} tTU=+*Io
catch(IOException e) P9T5L<5
{ .Yw'oYnS
e.printStackTrace (); F]O$(7*
} Su 5>$
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fh^lO ^
return n; @xc',I
} :R.&`4=X
(RtueEb.~E
rWh6RYd<T
} Q?AmOo-a
N$[$;Fm:
lgpW@g
/* _bD/D!|
**SiteInfoBean.java =+w*gDr
*/ ;L&TxO>#J
package NetFox; E\m5%bK\B
M,}|tsL
.@Ut?G
public class SiteInfoBean { pWu LfX
34!dYr%
RI2f`p8k
private String sSiteURL; //Site's URL 'Peni1_
private String sFilePath; //Saved File's Path >R/$1e1Y
private String sFileName; //Saved File's Name Z/rTVAs@r
private int nSplitter; //Count of Splited Downloading File #yI.nzA*
PR|R`.QSs
,#W
public SiteInfoBean() 5<L_|d)0"
{//nSplitter的缺省值为5 |y20Hi':
//default value of nSplitter is 5 m5G\}8|
this("","","",5); 2&Nb
} $BmmNn#
-*2Mf Mh
&_5tqh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1c+]gIe
{ {YUIMd!Y
sSiteURL= sURL; wW?,;B'74
sFilePath = sPath; XBQ\_2>
sFileName = sName; #"fJa:IYG7
this.nSplitter = nSpiltter; ob_I]~^I?|
fIF<g@s
r}yG0c,
} %r)avI
F_uY{bg
3?E8\^N\n
public String getSSiteURL() lt$zA%`odc
{ . |*f!w}5
return sSiteURL; H UoyLy
} !6&W,0<
`MP|Ovns:H
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public void setSSiteURL(String value) fri0XxF
{ R_sC! -
sSiteURL = value; 2wqk,c[]
} 8vk..!7n}
,7,g%?_P
MzIq"3
public String getSFilePath() e4OeoQ@ >
{ _ .i3,-l)
return sFilePath; >\ST-7[^L
} B5X sGLV
J/);"bg_O
$N2SfyX7
public void setSFilePath(String value) hC_Vts[v/
{ c.\O/N
sFilePath = value; G1 o70
} ^7]"kg DA
fQ>4MKLw=d
]aCk_*U
public String getSFileName() l!E7AKk8
{ #<( = }?
return sFileName; eK/?%t
} TST4Vy3
>Q,zNs
e7u^mJ
public void setSFileName(String value) ZV}X'qGaq
{ +D#Zn!P
sFileName = value; 8&"(WuZ@
} ;jK#[*y
}_QKJw6/"
f^e6<5gdf
public int getNSplitter() UkCnqNvx
{ =G~~?>=@2
return nSplitter; !A8^Xmz"
} -G &_^"=R
HEqWoV]{d
K7I&sS^x
public void setNSplitter(int nCount) 04!(okubyp
{ 7:=5"ScV
nSplitter = nCount; O$`UCq
} x}$e}8|8YL
} 6`\]derSon
y%]8'q$
a=GM[{og
/* "%8A:^1
**Utility.java A{o'z_zC
*/ uQLlA&I"
package NetFox; Y^"4?96
m8+(%>+7
l^NC]t
public class Utility { vjViX<#(V
bm&87
-7'#2P<)
public Utility() b'>8ZIY
{ ;i#LIHJ
\9)[#Ld
Mj0Cat=
} ?SY<~i<K-
FYPz 4K
//线程睡眠 E(+T*
public static void sleep(int nSecond) )&W|QH=AI
{ ^>~dlS
try{ !^U6Z@&/R
Thread.sleep(nSecond); {j(4m
} X7aXxPCq1
catch(Exception e) 6(56,i<#/
{ & %}/AoU
e.printStackTrace (); %/0gWG
} 2]jPv0u
} >L2*CV3p
Z$K+ 7>^
//日志 ucg$Ed
public static void log(String sMsg) g"t^r3
{ V*B0lI7`B
System.err.println(sMsg); 4".J/I5u
} #dJ 2Q_2
.+#Lx;})
Pw}_[[>$
public static void log(int sMsg) KS!yT_O
{ 993d/z|DX
System.err.println(sMsg); f==*"?6\
} 'ND36jHcRD
} FuP}Kec
":WYcaSi
V> a*3D
/* t/:w1rw
**TestMethod.java O4+F^+qN
*/ Rlg#z4m
package NetFox; j)D-BK&+
4e%8D`/=M
^E@@YV
public class TestMethod { '_Wt}{h
#MTj)P,
5}<[[}(
public TestMethod() %<U{K;
{ ///xx/weblogic60b2_win.exe .Vx|'-u
try{ GEE ]Kr
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Fn,k!q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); vnsSy33K
SiteFileFetch fileFetch = new SiteFileFetch(bean); (DJvi6\H
fileFetch.start(); g5R,% 6
} #4y,a_)
catch(Exception e){e.printStackTrace ();} A o3HX
i>Iee^_(
7Jx%JgF
} )*[ ""&
\REc8nsLy
^pcRW44K
public static void main(String[] args) ?iln<%G
{ @%B4;c
new TestMethod(); A^pW]r=Xtk
} G]lvHD
} wW()Zy0)
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