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)); itotn!Wb`
} 3jR>
for(int i=0;i<nEndPos.length-1;i++) JdYmUM|K/c
{ dOG]Yjc
nEndPos = nStartPos[i+1]; pX 4:WV
} ,EsPm'`?A/
nEndPos[nEndPos.length-1] = nFileLength; b{+7sl
} U-h'a: K
} |aWeo.;c
*aem5E`c
skSs|slp
//启动子线程 Dqxtc|vo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Gz09#nFZk
for(int i=0;i<nStartPos.length;i++) C6<*'5T
{ ~%gO+qD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SK][UxoHm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Wb)>APL
nStartPos,nEndPos,i); /kZ{+4M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +F>9hA
fileSplitterFetch.start(); ^jph"a C
} ioJ~k[T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {:@MBA34
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;pH&YBY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", iwiHw
nEndPos = " + nFileLength); ` @PHV
// fileSplitterFetch[nPos.length-1].start(); 40?xu#"
<q}w,XU
owR`Z`^h)
//等待子线程结束 Uj/m
//int count = 0; #saK8; tp
//是否结束while循环 ='rSB.$Ctk
boolean breakWhile = false; 7A,QA5G]C
n8K FP
S`w_q=-^8
while(!bStop) 9sQ#v-+Yx
{ E:7R>.g
write_nPos(); mQ$a^28=qR
Utility.sleep(500); EdC^L`::
breakWhile = true; Jm#mC
}Cs.Hm0P
[\_#n5
for(int i=0;i<nStartPos.length;i++) 4Y'Kjx
{ /7`fg0A
if(!fileSplitterFetch.bDownOver) 'gD,HX
{ 1J{1>r
breakWhile = false; ?^X e^1(
break; UZ*Yt
} *m>XtBw.
} jIvSjlmI
if(breakWhile) O,D/&0
break; \c1NIuJR
$E >)
Uo<iZ3J
//count++; DQ08dP((v
//if(count>4) 0m&
// siteStop(); |Q|vCWel{
} h=x{ 3P;B
TXH9BlDn
4tGP- L
System.err.println("文件下载结束！"); 5eL_iNqJM
} Qnr7Qnb
catch(Exception e){e.printStackTrace ();} VX'cFqrK3
} NA/hs/ '
;$FpxurX
)ZHo7X
//获得文件长度 PV(TDb:0
public long getFileSize() !et[Rdbu
{ n[f<]4<
int nFileLength = -1; IncHY?ud<
try{ }#bX{?f
URL url = new URL(siteInfoBean.getSSiteURL()); H)5V \
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MJ%gF=$X
httpConnection.setRequestProperty("User-Agent","NetFox"); {>]7xTpwZ
"d3qUk
;ND)h pD+
int responseCode=httpConnection.getResponseCode(); w(6(Fze
if(responseCode>=400) 0hCrEM!8
{ xRiWg/Z~
processErrorCode(responseCode); tqMOhR
return -2; //-2 represent access is error Z\1wEGP7{
} USrBi[_ci\
h ycdk1SN
QPZ|C{Ce
String sHeader; Vmb `%k20'
p$+.]
naaww
for(int i=1;;i++) IPTEOA<M[
{ q\I2lZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9FKowF_8
//Utility.log(in.readLine()); PKK18E}{%^
sHeader=httpConnection.getHeaderFieldKey(i); %=G*{mK
if(sHeader!=null) 15)y]N={^
{ lDU@Q(V#}<
if(sHeader.equals("Content-Length")) .$s>b#mO
{ dU<qFxW
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `9>1 w d
break; 9|K3xH
} (Z)F6sZ`8
} EWZ?q$
else H6Dw5vG"l
break; ]N#%exBVo
} 4xl}kmvv
} jjTb:Z=.'
catch(IOException e){e.printStackTrace ();} v "Yo
catch(Exception e){e.printStackTrace ();} id=:J7!QU
+m+v1(@
a*T=;P3(I
Utility.log(nFileLength); b$,~S\\c
>`S $(f
~L55l2u7
return nFileLength; <5fb,@YN
} MzP q(`W
)_-EeH
KhFw%Z0s<
//保存下载信息（文件指针位置） gOSFvH8FU
private void write_nPos() 2*5]6B-(
{ KJQW))%e
try{ V W2+ Bs}
output = new DataOutputStream(new FileOutputStream(tmpFile)); jSKhWxL;'
output.writeInt(nStartPos.length); d:"#_
for(int i=0;i<nStartPos.length;i++) 1{0 L~
{ 6|HxBC#4
// output.writeLong(nPos); Oh]RIWL
output.writeLong(fileSplitterFetch.nStartPos); W_\~CntyZ
output.writeLong(fileSplitterFetch.nEndPos); M7x*LiKc2
} tUXly|k
output.close(); Q.zE}ZS
} NAnccB D!{
catch(IOException e){e.printStackTrace ();} %c`P`~sp
catch(Exception e){e.printStackTrace ();} 3;t{V$
} 'G>gNq
(h$[g"8
Z H1UAf
//读取保存的下载信息（文件指针位置） Q}qw`L1
private void read_nPos() 9=FqI50{
{ qwd7vYBc,
try{ r}%2;!T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hP$v,"$
int nCount = input.readInt(); xoQ;fVNp
nStartPos = new long[nCount]; Pr_$%x9D
nEndPos = new long[nCount]; a|u&N:v7B
for(int i=0;i<nStartPos.length;i++) -rXo}I,VI
{ A6faRi703
nStartPos = input.readLong(); :rcohzfa
nEndPos = input.readLong(); <Z:Fnp
} )u67=0s2i+
input.close(); $(A LxC
} mQiVTIP3[O
catch(IOException e){e.printStackTrace ();} ]?"1FSu-8r
catch(Exception e){e.printStackTrace ();} +.Cx.Nf(
} >v9@p7Dn
%'`L+y
Xpp%j
private void processErrorCode(int nErrorCode) E,EpzB$_dj
{ 873'=m&
System.err.println("Error Code : " + nErrorCode); //O9}-
} R&P}\cf8T
<{"Jy)Uf
'}pe$=
//停止文件下载 H-ewO8@
public void siteStop() FcI ZG _
{ hF4gz*Q
bStop = true; E2%{?o
for(int i=0;i<nStartPos.length;i++) 27CVAX ghV
fileSplitterFetch.splitterStop(); 898=9`7e
\'[C_+;X
5<=ktA48[
} W%,h{
} FsTl@zN
//负责部分文件的抓取 J~=tR1k
**FileSplitterFetch.java XxeyGs^%9
*/ Duh[(r_
package NetFox; _ giZ'&l!
l<"Z?z
~IIlCmMl,
import java.io.*; r{1xjAT
import java.net.*; Sb,lY<=
@+EO3-X5
PYPDK*Ie
public class FileSplitterFetch extends Thread { uu`G<n
oD?c]}3
}bM=)eUfX
String sURL; //File URL DI,8y"!5
long nStartPos; //File Snippet Start Position !c#~g0H+
long nEndPos; //File Snippet End Position A!n)Fpk
int nThreadID; //Thread's ID DwBKqhu
boolean bDownOver = false; //Downing is over g]a5%8*{
boolean bStop = false; //Stop identical iF!r}fUU6
FileAccessI fileAccessI = null; //File Access interface x=jS=3$8
^`< %Pk
/~nPPC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?VaAVxd29
{ 8*[Q{:'.
this.sURL = sURL; l2[{T^
this.nStartPos = nStart; (Ymj
this.nEndPos = nEnd; ~P5;k_&
nThreadID = id; aNxq_pRb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5uxB)Dx)
} ^+b ??K
,'>,N/JA
WiBO8N,%`
public void run() pjaDtNb
{ JrhDqyk*
while(nStartPos < nEndPos && !bStop) klON6<w
{ b8$(j2B~
KB6'sj
o n+:{ad
try{ N{o3w.g
URL url = new URL(sURL); E>2~cC*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hnD=DLW $
httpConnection.setRequestProperty("User-Agent","NetFox"); cZd{K[fuK
String sProperty = "bytes="+nStartPos+"-"; /ltGSl
httpConnection.setRequestProperty("RANGE",sProperty); Gj9WUv[P
Utility.log(sProperty); WK)2/$7@
;E0aTV)Zp
:^H#i:4
InputStream input = httpConnection.getInputStream(); c(5r
//logResponseHead(httpConnection); fBZAO
<~ 9a3c?
nPh|rW=
byte[] b = new byte[1024]; ER4j=O#
int nRead; `:&jbd4H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B^yA+&3HI
{ Cg4l*"_
nStartPos += fileAccessI.write(b,0,nRead); hantGw|
//if(nThreadID == 1) "PhP1;A9,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xfsf
} kH9P(`;Vq
.*_uXQ
O>)Fl42IeD
Utility.log("Thread " + nThreadID + " is over!"); p.50BcDg
bDownOver = true; 2zQ62t}
//nPos = fileAccessI.write (b,0,nRead); V\4zK$]
} ` 0}z ;&:
catch(Exception e){e.printStackTrace ();} ;kv/(veQ1<
} [n!5!/g>j
} XI"8d.VR
K[/sVaPZ
[8OQ5}do/
//打印回应的头信息 3|qT.QR`Z
public void logResponseHead(HttpURLConnection con) hCvK2Xu
{ R3,O;9i
for(int i=1;;i++) dnXre*rhz
{ wx2EMr
String header=con.getHeaderFieldKey(i); ~[H+,+XLY+
if(header!=null) Fu;\t 0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7%g8&d
Utility.log(header+" : "+con.getHeaderField(header)); XNd%3rm,
else rm"C|T4:V
break; o{n)w6P{R,
} L2GUrf
} ln~;Osb
M}cgVMW
:\sz`p?EC
public void splitterStop() "jFRGgd79
{ g$P<`.
bStop = true; IA$)E
} %40uw3
BZr$x8%ki
ecg>_%.>
} k.MAX8
MfJ8+3@K
Nu]&?
/* &R7N^*He
**FileAccess.java \f6@B:?y
*//文件访问(定位，写) t<%S_J\
package NetFox; q5D_bm7,3
import java.io.*; 6Uik>e7?
njoU0f1`
vy&< O
public class FileAccessI implements Serializable{ H,Ik&{@j
F[HMX4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rQ+2 -|#
RandomAccessFile oSavedFile; 8;vpa*
long nPos; o fw0_)!Q
~lSdWUk>
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public FileAccessI() throws IOException WhY8#B'?
{ xP+HdA2X
this("",0); |1z?#@BH
} V <;vy&&
H)u<$y!8
Frxim
public FileAccessI(String sName,long nPos) throws IOException A3jT;D9Y%
{ D;RZE
oSavedFile = new RandomAccessFile(sName,"rw"); aOWfu^&H:
this.nPos = nPos; kl&9M!;:n
oSavedFile.seek(nPos); <ic%c/mN
} {y0`p1
s1/:Ts[3i
%8N=4vTJ
public synchronized int write(byte[] b,int nStart,int nLen) _Vj uQ
{ Ait3KIJ9
int n = -1; k 6)ThIG
try{ O,>`#?
oSavedFile.write(b,nStart,nLen); 6L\?+=X
n = nLen; /ZcqKC
} :% o32
catch(IOException e) H7=[sL^
{ 6gSo>F4=
e.printStackTrace (); gr%!<2w
} Ln2dD>{2
O5;$cP:
luYa+E0
return n; fsr0E=nV
} | D?lF
a`:ag~op@&
icnc5G
} a*fUMhIi
TGe)%jZ
fQ@k$W\
/* \4B2%H
**SiteInfoBean.java /'S@iq
*/ n,.ZLuBEX
package NetFox; &q?A)R
liuF;*
EP;TfWc}1
public class SiteInfoBean { B > sTM
$2?10}mrx
\@ jYY~
private String sSiteURL; //Site's URL nKP[U=ac
private String sFilePath; //Saved File's Path Ba]J3Yp,z
private String sFileName; //Saved File's Name yhBf%m
private int nSplitter; //Count of Splited Downloading File a/(IvOy#6
/%'>?8/
oK!W<#
public SiteInfoBean() zURob MpE#
{//nSplitter的缺省值为5 6)QJms
//default value of nSplitter is 5 |KM<\v(A{
this("","","",5); p?q~.YY
} T{VdlgL
E(l'\q'.
2d`:lk%\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N=`xoF
{ /J-:?./
sSiteURL= sURL; mROXwzL
sFilePath = sPath; _Coh11
sFileName = sName; IQz:DJ
this.nSplitter = nSpiltter; +/L "A
qg(rG5kD@
/61P`1y(J
} D{4Ehr "T
xK3 xiR
cc"L> XoK
public String getSSiteURL() w,'"2^Cwy
{ Fa!6*K\
return sSiteURL; 3*DwXH+
} BV9%|
f8m%T%]f
`(RQh@H
public void setSSiteURL(String value) ylEQeN
{ BgzER[g|q{
sSiteURL = value; v@6TC1M,
} C9`J6Uu
@y#QHJ.j
?Cu1"bl
public String getSFilePath() 7xmyjy%c
{ :n4X>YL)
return sFilePath; :4ndU:.L
} n$ri:~s
(($"XOU
|#r[{2sS
public void setSFilePath(String value) ?&H1C4
{ TvEN0RV2
sFilePath = value; (Nky?*
} +&w=*IAKZ
q $Hg\ {c
e2SU)Tr%b
public String getSFileName() |+^-b}0
{ fCA/
return sFileName; *=-o0c
} T%%+v#+
E>BP b
qrFC4\q}
public void setSFileName(String value) b :Knc$
{ $7#N@7
sFileName = value; q 16jL,i
} a!;]9}u7
@Gs*y1
t5%\`Yo?
public int getNSplitter() *mc]Oa
{ 2^Tj@P7
return nSplitter; T@n-^B!Xq
} Zl0Kv*S
C3Hq&TVf/
QFI8|i@
public void setNSplitter(int nCount) ,C#Mf@b
{ ?:Y0#Btj
nSplitter = nCount; G%a8'3d,
} kH!I&4d&
} hLVS}HE2
iXN7+QO)
[w%MECTe
/* 8-N8v *0
**Utility.java RaKfYLw
*/ $II[b-X?S
package NetFox; I[~EQ{Iz
6AZJ,Q\E@
]7QRelMiz+
public class Utility { B%v2)+?@
X(-e-:B4;
Y* #'Gh,
public Utility() kAbkhZ1^
{ z2m%L0
1_Um6vS#
TJ:B_F*bSk
} x*H4o{o0
\haJe~
//线程睡眠 $c-h'o
public static void sleep(int nSecond) &S}i)Nu6J
{ TzXivE@mm
try{ [<)/ c>Y
Thread.sleep(nSecond); )`RF2Y-A7
} `"0#lZ`n
catch(Exception e) x?J- {6k
{ 't$(Ruw
e.printStackTrace (); IT,TSs/Y
} /t-m/&>
} +$MNG
H61,pr>
//日志 8oSndfV
public static void log(String sMsg) $XFiH~GI
{ XE_|H1&j
System.err.println(sMsg); tHSe>*eC
} {x $H#<Y
,x| 4nk_
/znW$yh o
public static void log(int sMsg) ,}!OJyT
{ 8>Xyz`$kH
System.err.println(sMsg); ~jab/cR
} _y}]j;e8>{
} Azx4+`!-
q$EicH}k8
IqK??KSC
/* aU]A#g
**TestMethod.java pYo]lO
*/ $_-f}E
package NetFox; h+k:G9;sS
tT}*%A
AL/q6PWi
public class TestMethod { \UI7H1XDH
]X,C9
[&n2 yt
public TestMethod() m~%\f8w-x
{ ///xx/weblogic60b2_win.exe p=U*4[9k
try{ *0)vsBi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +#gJ[Cc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /I{<]m$
SiteFileFetch fileFetch = new SiteFileFetch(bean); j]EeL=H<P
fileFetch.start(); a3i4eGT-
} 2R&msdF
catch(Exception e){e.printStackTrace ();} |3f?1:"Z
=6b^j]1
&B uO-
} SxLu<
gc-yUH0I
o5gt`H"
public static void main(String[] args) _tZT
{ )s6pOxWx
new TestMethod(); c>~"Z-VtX
} WjxOM\?#
} "?|sC{'C4j
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