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)); tv2dyC&a
} 9HE)!Col
for(int i=0;i<nEndPos.length-1;i++) SYL$?kl
{ ;P_Zen
nEndPos = nStartPos[i+1]; P/Zo
} ]~P?
nEndPos[nEndPos.length-1] = nFileLength; @lX)dY
} 9pgct6BO
} 0[];c$r<
uFqH_04
aE"t['
//启动子线程 Wac8x%J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !m;VWGl*
for(int i=0;i<nStartPos.length;i++) rtpjx%
{ l>ttxYBa<d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qi%A/~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z 4-wvn<*
nStartPos,nEndPos,i); %lPP1 R
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DM&"oa50
fileSplitterFetch.start(); #FcYJH
} oAL-v428
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X DX_c@U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TCEbz8ql
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;@L#0
nEndPos = " + nFileLength); F ;D_zo?
// fileSplitterFetch[nPos.length-1].start(); %>.v[d1c
_#_Ab8#
+G~b-}
//等待子线程结束 #k6;~
//int count = 0; =p"0G%+%
//是否结束while循环 ,rd+ dN
boolean breakWhile = false; 'e*C^(6
5~kf:U%~
0kkiS3T
while(!bStop) 25(\'484>
{ nRGH58
write_nPos(); $`
Utility.sleep(500); "$)2|
breakWhile = true; 1a<,/N}}t
^2=zp.)
DlP}Fp{
for(int i=0;i<nStartPos.length;i++) 4-m%[D |W
{ 3FdoADe{{
if(!fileSplitterFetch.bDownOver) QZ6M,\
{ 8_lD*bEt
breakWhile = false; ^K"`k43{
break; ]?r8^LyZ4
} i8{jMe!Sa
} 5&>(|Y~I
if(breakWhile) jK{MU) D+
break; !xvPG
CtfSfSAUuu
zQ[mO
//count++; GA|q[<U
//if(count>4) SbZk{lWcq
// siteStop(); |qr[*c3$1
} SlZu-4J.-
=$'Zmb [D
+)|2$$m
System.err.println("文件下载结束！"); {p-%\nOC
} KpE#Ye&
catch(Exception e){e.printStackTrace ();} YPM>FDxDB
} TnG"_VK9R
IV*}w"r
p+t8*lkq
//获得文件长度 Zy#r<j]T
public long getFileSize() ]-6 G'i?
{ Li'T{0)1)
int nFileLength = -1; f 6q@
try{ \u*,~J)z
URL url = new URL(siteInfoBean.getSSiteURL()); !y),| #7P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %:y-"m1\u$
httpConnection.setRequestProperty("User-Agent","NetFox"); YMWy5 \
+)Ty^;+[1
YT_kMy>
int responseCode=httpConnection.getResponseCode(); &F:7U!
if(responseCode>=400) =_XcG!"
{ +n:#Uf)
processErrorCode(responseCode); M}c_KFMV
return -2; //-2 represent access is error $xl*P#
} " JRlj
#?/.LMn{
$^l=#tV
String sHeader; &a0%7ea`.S
F^\v`l,
Bj2rA.M
for(int i=1;;i++) ?{[H+hzz0
{ 6!'yU=Z`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :eO]65N
//Utility.log(in.readLine()); }}]Y mf
sHeader=httpConnection.getHeaderFieldKey(i); F-X>|oK>z
if(sHeader!=null) & #|vGhA
{ rS jC/O&b
if(sHeader.equals("Content-Length")) qEpBzQ&gX6
{ g&[g?L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9\;EX
break; V *]!N
} #4Z$O(
} Vlf@T
else 5 909O
break; 6nDx;x&Q
} (lm/S_U$
} L{=z}QO
catch(IOException e){e.printStackTrace ();} P~#jvm!
catch(Exception e){e.printStackTrace ();} #K[ @$BY:
qq/Cn4fN8
1Tl("XV3
Utility.log(nFileLength); 8]c`n!u=`
!6KEW,
A#i-C+"}
return nFileLength; 2H /a&uo@n
} ep^0Cd/
5x: XXj"
2rH6ap
//保存下载信息（文件指针位置） |N g[^
private void write_nPos() 3o?Lz7L
{ "6}+|!"$
try{ >5j/4Ly
output = new DataOutputStream(new FileOutputStream(tmpFile)); tEeMl =u
output.writeInt(nStartPos.length); +`+a9+=
for(int i=0;i<nStartPos.length;i++) D3Mce|t^
{ aT0 y
// output.writeLong(nPos); k"U4E J{
output.writeLong(fileSplitterFetch.nStartPos); 3ZVfZf
output.writeLong(fileSplitterFetch.nEndPos); q8D1MEBL`
} [brrziZ
output.close(); @!S$gTz
} EAI[J&c
catch(IOException e){e.printStackTrace ();} :K~7BJ(HO
catch(Exception e){e.printStackTrace ();} WZMsmhU@T
} iO@wqbg$6
^Nu} HcC+
(UM+?]Qwy
//读取保存的下载信息（文件指针位置） #i,O "`4
private void read_nPos() v:>P;\]r9M
{ `Ctj]t
try{ HlO+^(eX
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ju\"l8[f
int nCount = input.readInt(); NX;&V7
nStartPos = new long[nCount]; '71btd1
nEndPos = new long[nCount]; J0K"WmW
for(int i=0;i<nStartPos.length;i++) H0HYb\TX?
{ `3OGCy
nStartPos = input.readLong(); Bb o*
nEndPos = input.readLong(); 9f@)EKBK
} 0(kp>%mbB
input.close(); +u#x[xO
} 7%'<}u
catch(IOException e){e.printStackTrace ();} |RmBa'.)z
catch(Exception e){e.printStackTrace ();} ?m!FM:%
} .jKO 6f
1-n0"lP~4
+~@Y#>+./l
private void processErrorCode(int nErrorCode) l\5NuCgRY
{ IlrmXSr
System.err.println("Error Code : " + nErrorCode); ' 4"L;){:L
} O^GXFz^
7'I7
3:gk:j#
//停止文件下载 5Zov<+kE
public void siteStop() 1K`A.J:Uy
{ :o:??tqw
bStop = true; u"%fz8v
for(int i=0;i<nStartPos.length;i++) d !H)voX
fileSplitterFetch.splitterStop(); *G^]j )/
*+AP}\p0F
-'(:Sq,4o
} (}:xs,Ax
} U]acm\^Z
//负责部分文件的抓取 [>0r'-kI
**FileSplitterFetch.java +M*a.ra0OF
*/ 8M|Q^VeT,1
package NetFox; 7Tbkti;
F)@<ZE
B_S3}g<~
import java.io.*; bo2Od
import java.net.*; !8g y)2
NO$Nl/XM
*.RVH<W=8
public class FileSplitterFetch extends Thread { UXP;'
-&?-
/p>[$`Aq
String sURL; //File URL -%.V0=G(Z
long nStartPos; //File Snippet Start Position iH>djGhTh
long nEndPos; //File Snippet End Position mm8O
int nThreadID; //Thread's ID { SfU!
boolean bDownOver = false; //Downing is over $W]bw#NH
boolean bStop = false; //Stop identical Oc.>$
FileAccessI fileAccessI = null; //File Access interface H]e 2d|
\a!<^|C&
|#wz)=mD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0 Yp;?p^
{ A@ME7^w7
this.sURL = sURL; D\R^*k@V
this.nStartPos = nStart; J[l K
this.nEndPos = nEnd; N;HvB:c
nThreadID = id; *"ShE=\p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0u_'(Z-^2
} +[ zo2lBx
^Ram8fW
w(D9'
public void run() hd~rC*I
{ 5IK@<#wE
while(nStartPos < nEndPos && !bStop) 2. _cEY34
{ 9m6j?CFG}
6,PLzZ5
3[0:,^a
try{ je-s%kNlJ
URL url = new URL(sURL); B^9 #X5!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .yPx'_e
httpConnection.setRequestProperty("User-Agent","NetFox"); Vz*'^=(o&
String sProperty = "bytes="+nStartPos+"-"; U&R$(k0zS
httpConnection.setRequestProperty("RANGE",sProperty); BpT&vbY
Utility.log(sProperty); BXY'%8q _a
GN0'-z6Uy
5b,98Q
InputStream input = httpConnection.getInputStream(); gL`SZr9
//logResponseHead(httpConnection); 0^[6
#pfosC[
i"xDQ$0G6
byte[] b = new byte[1024]; %a `dOEO
int nRead; .Q@"];wH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %Qq)=J<H;
{ 6K}=K?3Z
nStartPos += fileAccessI.write(b,0,nRead); iE(grI3
//if(nThreadID == 1) =HHg:"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _=5ZB_I
} v%5(-
/3]|B%W9
3)Y:c2
Utility.log("Thread " + nThreadID + " is over!"); Hw{Y.@)4R
bDownOver = true; 1tW:(~=a;
//nPos = fileAccessI.write (b,0,nRead); d}_c(
} 7w,FA
catch(Exception e){e.printStackTrace ();} =*jcO119L
} x3|'jmg
} v=VmiBq[
b`zf&Mn
u#~!%~
//打印回应的头信息 ?miM15XI
public void logResponseHead(HttpURLConnection con) RZA\-?cO)
{ @k<~`S~|
for(int i=1;;i++) 3G^Ed)JvE
{ *.g?y6d
String header=con.getHeaderFieldKey(i); dL(|Y{4
if(header!=null) mC`! \"w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q;.]e#wvh
Utility.log(header+" : "+con.getHeaderField(header)); K5&C}Ey1
else LnS>3$t*
break; MFuI&u!g:
} +`-a*U94
} /MH@>C _
Z"X*FzFo
,np`:fBMy
public void splitterStop() )AXH^&
{ PBtU4)
bStop = true; E e>j7k.G.
} uW=NH;u
"~C#DZwt{
D5u"4\g<&
} #Ca's'j&f
*(B[J
<t% A)L%
/* VY@hhr1s~
**FileAccess.java g/p9"eBpq
*//文件访问(定位，写) 9'g{<(R]
package NetFox; 2j1v.%
import java.io.*; 3ohcHQ/a
(y*X8
GK?R76d
public class FileAccessI implements Serializable{ y$o=\:
pVS2dwBqE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }c ;um
RandomAccessFile oSavedFile; !!%[JR)cS
long nPos; Wy*7jB
kTWg31]~
9t.yP;j\Y
public FileAccessI() throws IOException jSp&mD*xv
{ +|)1_NK
this("",0); x=Jn&4q
} 6xh#;+e}
_PUm Pom.
cu!bg+,zl
public FileAccessI(String sName,long nPos) throws IOException Mk/!,N<h#
{ h./vTNMc
oSavedFile = new RandomAccessFile(sName,"rw"); )=nPM`Jn.
this.nPos = nPos; !r obau7
oSavedFile.seek(nPos); /(ju
} O)%kl
[.xk
cjC6\.+l3
public synchronized int write(byte[] b,int nStart,int nLen) =v$s+`cP
{ KGmc*Jwy
int n = -1; wn|@D<
try{ ^@L l(?
oSavedFile.write(b,nStart,nLen); I7z/GA\x
n = nLen; p6*a1^lU6
} U9.=Ik
catch(IOException e) &d3'{~:
{ MI'l4<>u
e.printStackTrace (); PJ'lZu8?x
} V,"iMo
3(})uV
ivz?-X4]
return n; w<>6>w@GZ
} ?En| _E_C
&Z;8J @
RG r'<o)
} Po11EZa$a
-s%-*K+,W
WfT)CIKs
/* iSz@E&[X
**SiteInfoBean.java m2q;^o:J
*/ 'h6}cw+K
package NetFox; fMEv85@JL
aU<D$I
*8X9lv.Z
public class SiteInfoBean { qvU$9cTY
G<-9U}~76
yX.5Y|A<
private String sSiteURL; //Site's URL ph12x: @B
private String sFilePath; //Saved File's Path ]n]uN~)9
private String sFileName; //Saved File's Name dFP-(dX#
private int nSplitter; //Count of Splited Downloading File |k .M+
@W\4UX3dK
ddq 1NW
public SiteInfoBean() 1;:t~Y
{//nSplitter的缺省值为5 @23RjoK
//default value of nSplitter is 5 gLSG:7m@
this("","","",5); `TD%M`a
} ?I2k6%a
?WQd
Fr3d#kVR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pG F5aF7T
{ CziaxJ
sSiteURL= sURL; x"llX
sFilePath = sPath; g[wP!y%V
sFileName = sName; *JY`.t
this.nSplitter = nSpiltter; O})u'
N~S[xS?
t>6x)2,TC
} B#k3"vk#
g\\1C2jG
' MS!ss=r
public String getSSiteURL() 3Da,]w<
{ s 9|a2/{
return sSiteURL; @Tfwh/UN
} | 2.e0Z]k
j`|^s}8t
4&oXy,8LC
public void setSSiteURL(String value) ,+\4 '`
{ vJj:9KcP>h
sSiteURL = value; by|?g8
} 9 yW~79n
N5f0|U&
tf7v5iGe
public String getSFilePath() <5ft6a2fQ
{ %eJ\d?nw
return sFilePath; 3r-VxP 5n
} }}``~
PJK]t7vp
fY%M=,t3c
public void setSFilePath(String value) Z.aLk4QO@
{ wj#J>C2]
sFilePath = value; .YjrV+om1
} i{|lsd(+
BbXU|QtY
|z#m
public String getSFileName() Iu-'o
{ gY>;|),
return sFileName; 65waq~#
} uP(B<NfL:'
J)$&z*!
S)\JWXi~:J
public void setSFileName(String value) @[5_C?2
{ $#G6m`V
sFileName = value; 'Vm5Cs$
} z)&naw.
49xp2{
?z5ne??
public int getNSplitter() !c4)pMd
{ sP6 ):h
return nSplitter; ![a/kj
} Wkg*J3O
462!;/y
192.W+H<
public void setNSplitter(int nCount) L,b|Iq
{ Ws^+7u
nSplitter = nCount; RRS~ xOg
} %\X P:
} !cN?SGafZI
;Na8_}
k1f3?l vlU
/* S_T{L
**Utility.java $ DDSN
*/ } g3HoFC
package NetFox; QmH/yy3.%
d7W%zg\T
FX|0R#4vm
public class Utility { FylWbQU9
/'Quu)~
*=$[}!YG
public Utility() CdBthOPX)
{ Wj&<"Z6'm(
k_*XJ<S!Y
VO.-.
} b?Cmc
2!{_/@I\Y
//线程睡眠 'GV&]
public static void sleep(int nSecond) ER~T'-YMS
{ E6'8Zb
try{ 3AdP^B<
Thread.sleep(nSecond); x1 ;rb8
} &5kZ{,-eM
catch(Exception e) gB/;clCdX)
{ &7L~PZ
e.printStackTrace (); (MgL"8TS
} ur/Oc24i1n
} H o4B
r+p@X
//日志 xZ^ywa_
public static void log(String sMsg) 51o@b
{ \g~ws9'~
System.err.println(sMsg); _L*f8e8
} U9<_6Bsd
?-pxte8
P<>[e9|
public static void log(int sMsg) %'{V%IXQ
{ /J1S@-
System.err.println(sMsg); -]Q3/"Q
} {[Uti^)m%
} %:" RzHN
Jq#[uX
Rz`@N`U
/* v\fzO#vj
**TestMethod.java |f"-|6
*/ q$MHCq;
package NetFox; |9+bSH9
_n< LVdE
>lA7*nn
public class TestMethod { ?D1x;i9<
+DicP"~*
gb]hOB7g
public TestMethod() @kwLBAK}@
{ ///xx/weblogic60b2_win.exe sEoZ1E
try{ N1YgYL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S#P+B*v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^Lsc`<xC
SiteFileFetch fileFetch = new SiteFileFetch(bean); *GCA6X
fileFetch.start(); |tG05+M
} D4AEZgC F,
catch(Exception e){e.printStackTrace ();} IgLVn<5n
])N|[|$
sk#9x`Rw
} jz %;4e~t
p9/bzT34.
BD hLz
public static void main(String[] args) !$D&6M|C8l
{ w|&,I4["
new TestMethod(); :0B |<~lX
} |$M@09,F"
} !-KCFMvT
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