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)); 2#/ KS^
} ]Wd{4(b
for(int i=0;i<nEndPos.length-1;i++) 42z9N\ f
{ ?N11R?8
nEndPos = nStartPos[i+1]; 7MGc+M(p
} BC@"WlD
nEndPos[nEndPos.length-1] = nFileLength; Crpkq/M
} ::TUSz2/2
} bL0+v@(r
DMf^>{[
i":-g"d
//启动子线程 NPB':r-8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NLz$jk%=g
for(int i=0;i<nStartPos.length;i++) Qs%f6rL
{ B|,6m 3.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KL5rF,DME
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~PlwPvWo
nStartPos,nEndPos,i); OPKX&)SE-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [&{"1Z
fileSplitterFetch.start(); 9s*Lzi[}
} E\V>3rse
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ni%^w(J3Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;"Ot\:0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *D<sk7
nEndPos = " + nFileLength); }FM<uBKW
// fileSplitterFetch[nPos.length-1].start(); <mm}IdH
~Dy0HVE
w-\fCp )
//等待子线程结束 nosEo?{
//int count = 0; m};_\Db`
//是否结束while循环 -w@fd]g
boolean breakWhile = false; PA5g]Tz
`J-"S<c?_
' >\*
while(!bStop) p{-1%jQ}]
{ A<TJ3Jp]
write_nPos(); ![vc/wuf
Utility.sleep(500); 1H[lf B
breakWhile = true; |23 }~c,
<K97eAcW
p:4vjh=1h
for(int i=0;i<nStartPos.length;i++) eM9~&{m.
{ jG.*tuf
if(!fileSplitterFetch.bDownOver) RMi 2Ip
{ LXXxwIBS
breakWhile = false; p19Zxh
break; uWfse19
} U| N`X54
} 6B+ @76wH
if(breakWhile) a:;*"p[R
break; Y7{|EI+@
vfy-;R(
oOUVU}H
//count++; rg'? ?rq
//if(count>4) Pc(2'r@#
// siteStop(); 3BSeZ:j7
} s-C.+9
M?\)&2f[Z
F~DG:x~
System.err.println("文件下载结束！"); Ffhbs D
} uj:w^t ][
catch(Exception e){e.printStackTrace ();} Y]Fq)-
} "RShsJZMH
{(tE pr
#Se
//获得文件长度 )0GnTB;5Z
public long getFileSize() q7)$WXe2LM
{ 6Nl$&jL
int nFileLength = -1; l y%**iN
try{ w"BTu-I
URL url = new URL(siteInfoBean.getSSiteURL()); %(kq Hxc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RB\WttI
httpConnection.setRequestProperty("User-Agent","NetFox"); E""/dC:B
HOUyB's'
! \gRXP}
int responseCode=httpConnection.getResponseCode(); oqY?#p/
if(responseCode>=400) Xoik%T-
{ b%_QL3m6
processErrorCode(responseCode); +(/Z=4;,[
return -2; //-2 represent access is error 1a)_Lko
} ad~ qr n\
GqAedz;.
F9c2JBOM
String sHeader; xH f9N?
sEj:%`l|
T,IV)aq
for(int i=1;;i++) wM yPR_
{ #k"[TCQ>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ( ou:"Y
//Utility.log(in.readLine()); sXydMk`J
sHeader=httpConnection.getHeaderFieldKey(i); Bdg*XfXXk
if(sHeader!=null) M84LbgGM%
{ a-}%R
if(sHeader.equals("Content-Length")) 54;iLL
{ Sx~_p3_5U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); RXof$2CZS
break; '~f@p~P
} cp2fDn
} HdLkof2i
else wYxizNv,
break; ef.lM]cO
} .kYzB.3@]
} ?ykZY0{B
catch(IOException e){e.printStackTrace ();} ,-1$Vh@wM
catch(Exception e){e.printStackTrace ();} GS$k
FvNO*'xP
i&30n#
Utility.log(nFileLength); C>u 3n^
>4VU
!'gz&3B~h
return nFileLength; bOFLI#p&
} 0iE).Za0g
;`+RSr^8$
sogbD9Jc
//保存下载信息（文件指针位置） M$?6 '
private void write_nPos() 5ya3mNE
{ nn
try{ x2B"%3th0
output = new DataOutputStream(new FileOutputStream(tmpFile)); C&st7. (k
output.writeInt(nStartPos.length); -#o+x Jj
for(int i=0;i<nStartPos.length;i++) $oQsh|sTI
{ 6P~"7k
// output.writeLong(nPos); (g)@wNBW
output.writeLong(fileSplitterFetch.nStartPos); &59#$LyH`%
output.writeLong(fileSplitterFetch.nEndPos); 6^aYW#O<Ua
} b mm@oi
output.close(); 6m" 75
} 1h#k&r#*3
catch(IOException e){e.printStackTrace ();} qN0#=X
catch(Exception e){e.printStackTrace ();} M+E5PZ|_
} I>3]4mI*a
4GfLS.Ip
ygW@[^g
//读取保存的下载信息（文件指针位置） 'f}S,i +q
private void read_nPos() ]p*) PpIl
{ vedMzef[@>
try{ _Ry.Wth
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _%2Umy|
int nCount = input.readInt(); pzax~Vp
nStartPos = new long[nCount]; <D dHP
nEndPos = new long[nCount]; 0V#t ;`Q3
for(int i=0;i<nStartPos.length;i++) 7, 13g)
{ 9HE(*S
nStartPos = input.readLong(); g"&bX4uD)
nEndPos = input.readLong(); ?|7+cz$g
} D{4hNO
input.close(); (rG1_lUDu
} {^kG<v.vV
catch(IOException e){e.printStackTrace ();} GA_`C"mx
catch(Exception e){e.printStackTrace ();} ?iLd5 Z
} ,?`1ve_K<
IeB6r+4|
NslA/"*
private void processErrorCode(int nErrorCode) H|)1T-%
{ :ky<`Jfr`
System.err.println("Error Code : " + nErrorCode); 9$,gTU_a
} Tb={g;0@
M96( Rg
V0 F30rK
//停止文件下载 zn ?;>Bl
public void siteStop() c9uT`h
{ !~N4}!X3du
bStop = true; w~U`+2a3
for(int i=0;i<nStartPos.length;i++) rc$!$~|I3Z
fileSplitterFetch.splitterStop(); mVK9NK
v|I5Gz$qpa
k4$q|x7+%
} KY`96~z
} <VU4rk^=
//负责部分文件的抓取 y,&M\3A
**FileSplitterFetch.java hcgc =$^
*/ o1WidJ"
package NetFox; qZJ*J+
ow_y
kNj3!u$
import java.io.*; V"H7zx
import java.net.*; NoO+xLHw8
unnx#e]
V*zz- 2_i
public class FileSplitterFetch extends Thread { klJ[ {p
F!&pENQ
~{vdP=/WP
String sURL; //File URL MgQU6O<
long nStartPos; //File Snippet Start Position "-n%874IT
long nEndPos; //File Snippet End Position +qj*P9
int nThreadID; //Thread's ID /HuYduGdP
boolean bDownOver = false; //Downing is over ZGpTw[5ql
boolean bStop = false; //Stop identical @pGlWw9*
FileAccessI fileAccessI = null; //File Access interface uT}TSwgp
b3b~T]]
8q [c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kr(<Y|
{ %W4aKb?BT
this.sURL = sURL; 2-V)>98
this.nStartPos = nStart; 8RAeJ~e
this.nEndPos = nEnd; 8M|)ojH
nThreadID = id; 2ly,l[p8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *fl{Y(_OO
} 6#)Jl
T_x+sv=|X!
WYC1rfd=
public void run() As+;qNO
{ 'K3s4x($
while(nStartPos < nEndPos && !bStop) vzcBo%
{ uR;-eK
l-S'ATZ0p
T5azYdzJy
try{ F[kW:-ne@Z
URL url = new URL(sURL); zZ9<4"CIk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9*|3E"Vr
httpConnection.setRequestProperty("User-Agent","NetFox"); *?bk?*?s
String sProperty = "bytes="+nStartPos+"-"; =kb6xmB^t
httpConnection.setRequestProperty("RANGE",sProperty); #t@x6Vt
Utility.log(sProperty); d{yIy'+0/
pf8O`e,Awf
$}nh[@
InputStream input = httpConnection.getInputStream(); '^Utbp2<
//logResponseHead(httpConnection); R6Zj=l[
8b(1ut{
!(*a+ur&i
byte[] b = new byte[1024]; 'q92E(
int nRead; IE)"rTI)b
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *NW QmC~
{ ;4G\]%c)E{
nStartPos += fileAccessI.write(b,0,nRead); t@(9ga(
//if(nThreadID == 1) /> 3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KR=d"t Qw
} 2]D$|M?$~
/c@*eU
>7nV$.5S
Utility.log("Thread " + nThreadID + " is over!"); V3mjbH>F
bDownOver = true; *IWFeu7y
//nPos = fileAccessI.write (b,0,nRead); r]8x;v1
} VyWYfPK
catch(Exception e){e.printStackTrace ();} ov`^o25f
} H^D 3NuUC
} X 45x~8f
ypD<2z^
z!s.9
//打印回应的头信息 +9zJlL^A%
public void logResponseHead(HttpURLConnection con) VW9>xVd4
{ UZje>.~?
for(int i=1;;i++) {}_Nep/;
{ oWp}O?
String header=con.getHeaderFieldKey(i); ZU|6jI}
if(header!=null) dP$8JI{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _ }E-~I>
Utility.log(header+" : "+con.getHeaderField(header)); %j'G.*TD
else #2PrGz]
break; *N-;V|{
} U~:N^Sc
} =.36y9Mfo
_F`$ d2
[ WV@w
public void splitterStop() Y=vVxVI\
{ B;Xoa,
bStop = true; 7fju
} t7w-TJvP
~u /aOd
&8<<!#ob
} 0R HS]cN
+yf(Rs)!
GilQtd3\
/* YV/>8*i
**FileAccess.java v7i^O`{eD?
*//文件访问(定位，写) d,c8Hs8
package NetFox; J~Cc9"(
import java.io.*; E/mubA(&
Ap5}5 ewM
3CR@' qG-
public class FileAccessI implements Serializable{ ;,1=zhKU.
4_PCqEp)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pOC% oj
RandomAccessFile oSavedFile; \ Md 3
long nPos; Fe!D%p Qv
^WE4*.(
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public FileAccessI() throws IOException F9(._ow[
{ T@TIzz
this("",0); _om0 e=5)
} AV40:y\RW
&v^!y=Bt
bIgh@= 2
public FileAccessI(String sName,long nPos) throws IOException P$Z}
{ '_:(oAi,C
oSavedFile = new RandomAccessFile(sName,"rw"); B*\$ /bk,
this.nPos = nPos; !FTNmyM~F
oSavedFile.seek(nPos); w8O" =},
} g;pR^D'M5C
jY7=mAd
+R-h ,$\=7
public synchronized int write(byte[] b,int nStart,int nLen) wfgqgPo!v
{ Ntb:en!X
int n = -1; pb!V|#u"
try{ aaDP9FW9e
oSavedFile.write(b,nStart,nLen); )Im3'0l>
n = nLen; Sw~(uH_l
} ^ eQFg>
catch(IOException e) |% z^N*
{ f-;$0mTQ
e.printStackTrace (); 0n Y6A~
} {esJ=FV\
U{6oLqwq3Y
_V@WNo%B
return n; HBH$
} i AdGgK
X) V7bVW
[4sEVu}
} 9Ycn0
xJ{_qP
vY6oVjM
/* XZ`:wmc|
**SiteInfoBean.java ,LDm8
*/ #05jC6
package NetFox; lVz9k
vw2`:]Q+
{_?rh,9q
public class SiteInfoBean { S,)d(g3>
k1)%.pt%
7BR8/4gcPu
private String sSiteURL; //Site's URL cHx%Nd\
private String sFilePath; //Saved File's Path JK]R*!{n
private String sFileName; //Saved File's Name h.)h@$d
private int nSplitter; //Count of Splited Downloading File dBSbu=^$)
v,=v
+ WVIZZ8
public SiteInfoBean() _A98
{//nSplitter的缺省值为5 !Uh2}ic
//default value of nSplitter is 5 <a4TO8
this("","","",5); As~(7?]r
} w~z[wmOkp
#2RiLht
/kgeV4]zR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G O{.9_2
{ *wuqa)q2
sSiteURL= sURL; !*aPEf270
sFilePath = sPath; u:&o}[
sFileName = sName; ~e `Bq>
this.nSplitter = nSpiltter; KzjC/1sd
]PWDE"
{ox2Tg?
} sV/l5]b]
O:'?n8rWL
+vW)vS[
public String getSSiteURL() :w`3cwQ
{ Kv37s0|g
return sSiteURL; g:7,~}_}^
} j~E",7Q'
20b<68h$:
Fk"Ee&H)(
public void setSSiteURL(String value) ~ Vw9
{ RBwO+J53y
sSiteURL = value; ]}Z4P-"t
} Ej=3/RBsV
Tlq-m2]
'm3t|:nMU
public String getSFilePath() !ErH~<f%K
{ 6KHN&P
return sFilePath; R\mR$\cS
} x}TS
p8}(kHUp(
POAw M
public void setSFilePath(String value) H#i{?RM@l
{ !}f1`/
sFilePath = value; g13 rx%-
} mO*^1
#>[a{<;Kn
q5x[~]?
public String getSFileName() 5O<>mCF
{ uR;gVO+QC
return sFileName; #m<tJnEO
} )yG"^Ulu
&<y2q/U}
fX~'Zk\u
public void setSFileName(String value) aAE>)#f(
{ :#5xA?=* S
sFileName = value; 6E~g#(8
} 2S"Nf8>zp
D&G"BZx|
2)X4y"l
public int getNSplitter() \Q~8?p+
{ Ea6 &~"
return nSplitter; tZyo`[La
} 0'5/K ,
Rk6deI]
({s6eqMhDd
public void setNSplitter(int nCount) S4UM|`
{ t5B7I59
nSplitter = nCount; 1'.7_EQ4T
} z~*g~RKS!
} @"-</x3o
e~l#4{w
;U9J++\d<A
/* 5xCT~y/a
**Utility.java 8:=n*
*/ B* kcNlW
package NetFox; P{OAV+cG
T9W`?A
rxnFrx
public class Utility { fKH7xu!V4+
\Ig68dFf%
K5Q43e1
public Utility() 3`E=#ff%
{ pM;vH]|
&H}r%%|A
gTl<wo +
} az0<5Bq)
}jH7iyjD
//线程睡眠 o?L'Pg
public static void sleep(int nSecond) YB<*"HxM)}
{ ;Uc0o!1
try{ qgIb/6;xQ
Thread.sleep(nSecond); >Y7a4~ufko
} `Z:R Ce^
catch(Exception e) N6K*d` o
{ [x=jH>Y
e.printStackTrace (); 7SDFz}
} PyVC}dUAX
} %^sTU4D5
1"Z@Q`}
//日志 4iAZ+l5&
public static void log(String sMsg) 'c2W}$q
{ De7Ts
System.err.println(sMsg); =4V&*go*\
} *B`Zq)
gE#>RM5D
j',W 64
public static void log(int sMsg) glDcUCF3
{ v+p{|X-
System.err.println(sMsg); 0a8/B>
} {3;AwhN0H
} &'cL%.
vEf4HZ&w
hfpJ+[
/* XL#[%X9
**TestMethod.java {{V8;y
*/ #^m0aB7r
package NetFox; =qN2Xg/
rpeJkG@+
SJD@&m%?[
public class TestMethod { 9T#;,{VQ
P96pm6H_;
+]=e;LN$0
public TestMethod() EY*(Bw
{ ///xx/weblogic60b2_win.exe fYKOJ5f
try{ C{TA.\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oFOnjK"|F
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %ZHP2j %~
SiteFileFetch fileFetch = new SiteFileFetch(bean); oFjIA!
fileFetch.start(); ;&H4u)
} >WY#4
catch(Exception e){e.printStackTrace ();} DN4$Jva
r0p w_j
YK|bXSA[
} [MuEoWrq(}
),%6V5a+E
wFG3KzEq ~
public static void main(String[] args) 8XbA'% o
{ @lJzr3}WZ
new TestMethod(); {vAE:W.s
} $w"$r$K9K
} /cc\fw1+
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