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)); s16, *;Z
} H8HVmfM
for(int i=0;i<nEndPos.length-1;i++) ?UOaqcL
{ /`nkz
nEndPos = nStartPos[i+1]; ]sE)-8
} piuM#+Y\'S
nEndPos[nEndPos.length-1] = nFileLength; H!OX1F
} & BY\h:
} %4V$')rek
kt\,$.v8
261? 8&c
//启动子线程 Oo FMOlb.Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q4G$I?4
for(int i=0;i<nStartPos.length;i++) XZ3fWcw[
{ W,H=K##6<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'Nuy/\[{\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P{:Zxli0
nStartPos,nEndPos,i); 2mMi=pv9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,=c(P9}^
fileSplitterFetch.start(); Q>9bKP
} ]\oT({$6B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1;i|GXY:h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4GG>n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^;9l3P{
nEndPos = " + nFileLength); =n_z`I
// fileSplitterFetch[nPos.length-1].start(); mW+5I-~
XzqB=iX
YktZXc?iI<
//等待子线程结束 j72mm!
//int count = 0; ^6F, lS_t
//是否结束while循环 z 0zB&}
boolean breakWhile = false; )PYh./_2
%|^,Q -i,
9ZatlI,
while(!bStop) v6[VdWOx5
{ fo`R=|L[
write_nPos(); , /jHhKW
Utility.sleep(500); ?D_iib7
breakWhile = true; o:"(\$
}bdoJ5
9V&+xbR&
for(int i=0;i<nStartPos.length;i++) m,62'
{ 6A|XB3
if(!fileSplitterFetch.bDownOver) yGrnzB6|
{ quC$<Y
breakWhile = false; 1@|%{c&+9
break; m']$)Iqw
} }u$c*}
} dTu*%S1Z
if(breakWhile) GM1.pVb
break; n9k
Nh/i'q/
*qAG0EM|
//count++; vWrTB
//if(count>4) ?EPHq, E
// siteStop(); WS(m#WFQr
} f8=qnY2j
d#$Pf=}
v.vkQQ0[9
System.err.println("文件下载结束！"); 7+@-mJMP$D
} &2[Xu4*
catch(Exception e){e.printStackTrace ();} L:mE)Xq2
} L;L_$hu)
}R5EuR m\
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//获得文件长度 x _d
public long getFileSize() gd#?rc*f<3
{ M8\/[R\
int nFileLength = -1; v@8SMOe%
try{ P?c V d2Y
URL url = new URL(siteInfoBean.getSSiteURL()); <1m`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o"L8n(\
httpConnection.setRequestProperty("User-Agent","NetFox"); *n# =3D
@JLN3
Qb%; |li
int responseCode=httpConnection.getResponseCode(); hNkv lk'Ui
if(responseCode>=400) PVdN)tG5
{ ~)>.%`v&
processErrorCode(responseCode); ZGI<L
return -2; //-2 represent access is error ?p 4iXHE
} V>E7!LIn.
c93 Ok|
&`vThs[x
String sHeader; kTT%< e
#.fJ M:"tG
_s5FYb#
for(int i=1;;i++) D)l\zs%ie
{ vlZmmQeJm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #Dz"g_d
//Utility.log(in.readLine()); p1i}fGS
sHeader=httpConnection.getHeaderFieldKey(i); cC|
if(sHeader!=null) V*(x@pF
{ X%JyC_~<
if(sHeader.equals("Content-Length")) ].aFdy
{ 0kls/^0,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $)PS#ND&
break; n_ ?+QF
} ,O-_Pv
} .m>Qlh
else 6GVAR
break; @2d9 7.X
} M.Tp)ig\#
} ?[>Y@we
catch(IOException e){e.printStackTrace ();} -'d`(G"
catch(Exception e){e.printStackTrace ();} +%KkzdS'
#Z `Tk)u/
5WxNH}{
Utility.log(nFileLength); (a-Lx2T
99By.+~pX
O0`ofFN
return nFileLength; AFvv+ ss
} 5rCJIl.
f?GoBh<
TvT>UBqj=
//保存下载信息（文件指针位置） 3B,dL|q(@J
private void write_nPos() ~]?EV?T
{ KydAFxUb
try{ 6@FhDj2X
output = new DataOutputStream(new FileOutputStream(tmpFile)); On!+7is'
output.writeInt(nStartPos.length); 5`Uzxu
for(int i=0;i<nStartPos.length;i++) DKem;_6OQ
{ jTV4iX
// output.writeLong(nPos); J.U%W}Hx
output.writeLong(fileSplitterFetch.nStartPos); @icw:68
output.writeLong(fileSplitterFetch.nEndPos); cq gCcO,
} AGS(ud{
output.close(); (e!Yu#-
} SAf)#HXa
catch(IOException e){e.printStackTrace ();} \dE{[^.5
catch(Exception e){e.printStackTrace ();} OK`^DIr5l
} PvjZoF["
`U\l: ~]e
F6Q%<p a
//读取保存的下载信息（文件指针位置） 8'TIDu
private void read_nPos() 7P*\|Sxk%
{ fi~@J`
try{ dV'^K%#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eX}aa0
int nCount = input.readInt(); /?XI,#j3kM
nStartPos = new long[nCount]; \Zx&J.D
nEndPos = new long[nCount]; EL z5P}L6
for(int i=0;i<nStartPos.length;i++) Ars*H,9>e
{ }0@@_Y]CC
nStartPos = input.readLong(); s?->2gxhx
nEndPos = input.readLong(); Y+vIU*O
} S# baOO
input.close(); P0hr=/h4
} *kTp(*K/7`
catch(IOException e){e.printStackTrace ();} ~7g$TAe{
catch(Exception e){e.printStackTrace ();} 8Exky^OT|
} Q!=`|X|:
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60A!Gob
private void processErrorCode(int nErrorCode) y x#ub-A8
{ ev+H{5W8
System.err.println("Error Code : " + nErrorCode); _zzNF93Bn
} !?+0O]`}
#=ij</
8No'8(dPX
//停止文件下载 <6,,:=#
public void siteStop() h>cjRH?e
{ cT/mi":8{
bStop = true; ;YMg4Cs
for(int i=0;i<nStartPos.length;i++) R;A8y
fileSplitterFetch.splitterStop(); ?P>4H0@I+
u#^l9/tl
k2,`W2]^E
} ,mi7WW9
} K4]ZVMm/*
//负责部分文件的抓取 5|Z8UzL
**FileSplitterFetch.java UhkL=+PD
*/ O#O"]A
package NetFox; `T7TWv"M
`l.bU3C
I2SH j6-
import java.io.*; o&z[d
import java.net.*; hDZyFRg
v.>K )%`#
l;R8"L:,p\
public class FileSplitterFetch extends Thread { ; 2V$`k
\*b .f
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String sURL; //File URL 94t`&jZ&|u
long nStartPos; //File Snippet Start Position r#&JfAo
long nEndPos; //File Snippet End Position &V+KM"Ow
int nThreadID; //Thread's ID X%(NI(+x,
boolean bDownOver = false; //Downing is over Ej6ho0_
boolean bStop = false; //Stop identical qP##C&+#q
FileAccessI fileAccessI = null; //File Access interface J65:MaS
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S-~)|7d.
{ z\8s |!
this.sURL = sURL; o:3(J}
this.nStartPos = nStart; >BK/HuS
this.nEndPos = nEnd; kw gLK@@%1
nThreadID = id; BYhiP/^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x^pt^KR;
} N'aq4okoL
]vs}-go
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public void run() "%a<+D
{ %, iAngF'
while(nStartPos < nEndPos && !bStop) 5/h-Hr
{ T{`VUS/
r%ebC
OW@)6
try{ ^EkxZ4*g
URL url = new URL(sURL); 7l=Tl[n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~OvbMWu
httpConnection.setRequestProperty("User-Agent","NetFox"); H<<t^,E^.t
String sProperty = "bytes="+nStartPos+"-"; mTUoFXX[
httpConnection.setRequestProperty("RANGE",sProperty); =2QP7W3mg<
Utility.log(sProperty); :&'jh/vRN
9y5JV3
r7R.dD/.
InputStream input = httpConnection.getInputStream(); =_m3~=Z
//logResponseHead(httpConnection); }BL7P-km
mv~?1aIKD
yqL"YD
byte[] b = new byte[1024]; kTI5CoXzq
int nRead; +r;t]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tCGx]\
{ &k)v/
nStartPos += fileAccessI.write(b,0,nRead); FPF$~ sX
//if(nThreadID == 1) M<NY`7$^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6<QC|>p
} t6mv
p[].4_B;
}mIN)o
Utility.log("Thread " + nThreadID + " is over!"); &IzNoB
bDownOver = true; Is<XMR|{
//nPos = fileAccessI.write (b,0,nRead); j%w^8}U>G
} hAc|a9 o
catch(Exception e){e.printStackTrace ();} *V\.6,^v
} EU|IzUjFj|
} (S+/e5c)
JR15y3F
-@`Ah|m@}
//打印回应的头信息 1ywdcg
public void logResponseHead(HttpURLConnection con) 19y,O0# _
{ 3#dz6+
for(int i=1;;i++) C#yRop_d]o
{ @H4]Gp ]
String header=con.getHeaderFieldKey(i); fsw[R0B
if(header!=null) \f(zMP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E"S#d&9
Utility.log(header+" : "+con.getHeaderField(header)); |o9`h9i
else C,$o+q*)W9
break; w%iwxo
} `sso Wn4
} W}3%BWn
} eHxw+.
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public void splitterStop() #Ktk["6
{ L97 ~ma
bStop = true; T`Up%5Dk
} BN%cX2j
%*npLDi
Z}\,rex
} 6S_mfWsi
3c,4 wyn
<;?1#ok
/* 39 zfbxX
**FileAccess.java U!uJ)mm
*//文件访问(定位，写) E0fMFG^P
package NetFox; ~|O;Sdo=
import java.io.*; )`'a1y|
S5ai@Ksf
Ay 4P_>^
public class FileAccessI implements Serializable{ {J,"iJKop
^0}wmxDq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s5mJ -
RandomAccessFile oSavedFile; 3F!)7
long nPos; *c/V('D/
m;{HlDez
!9KDdU
public FileAccessI() throws IOException g}R Cjl4
{ T8|?mVv s
this("",0); #5{xWMp/0
} KU oAxA
>bQOpGy}l
X`WS&!C<
public FileAccessI(String sName,long nPos) throws IOException Jj=N+,km
{ W'"?5} (
oSavedFile = new RandomAccessFile(sName,"rw"); )uo".n|n~B
this.nPos = nPos; 3%GsTq2o
oSavedFile.seek(nPos); $|J+
} AA=rjB9
4[]*=
glU9A39qx?
public synchronized int write(byte[] b,int nStart,int nLen) ^AJ 2Y_}v
{ V?"U)Y@Y
int n = -1; f"*4R kG
try{ =P9rOK=
oSavedFile.write(b,nStart,nLen); k\T]*A
n = nLen; KA{QGaZ/
} $b{8$<;9
catch(IOException e) JU5,\3Lz#
{ <X4f2z{T{@
e.printStackTrace (); H!X*29nX
} XXA'B{@Y)
aZ\Z7(
^w``(-[*
return n; >#;;g2UV
} 4~$U#$u_
sH2xkUp
XP%_|Q2X
} 7_qsVhh]$E
|ZifrkD=
VWK/(>TP
/* CL7/J[TS
**SiteInfoBean.java ;y@zvec4
*/ kJOZ;X=9/
package NetFox; : fYfXm
}wvRs5;o
Gsy>"T{CY
public class SiteInfoBean { |IzL4>m:;
L/WRVc6
iM:-750n/
private String sSiteURL; //Site's URL z(^dwMw}
private String sFilePath; //Saved File's Path .6 0yQ[aE
private String sFileName; //Saved File's Name NopfL
private int nSplitter; //Count of Splited Downloading File {cLWum[SY
Viw,YkC
Je9Z:s[
public SiteInfoBean() 2~g-k3
{//nSplitter的缺省值为5 F-ofR]|)>
//default value of nSplitter is 5 4f8XO"k7t=
this("","","",5); fSVM[
} # .(f7~
u^E0u^
ELMz~vp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E)jd>"
{ Bd=K40Z:
sSiteURL= sURL; (,+#H]L
sFilePath = sPath; md18q:AG)
sFileName = sName; B= E/|J</
this.nSplitter = nSpiltter; *)^ZUk
d$+0;D4E
S["r @<
} ip{b*@K
XfMUodV-OZ
AU%Yr6
public String getSSiteURL() p=x&X~
{ 6}c!>n['
return sSiteURL; o(l%k},a
} )AdwA+-x
:KG=3un]
tCR~z1
public void setSSiteURL(String value) m3P7*S5NJ7
{ ^*$!9~
sSiteURL = value; IV':sNV
} ~.U\Y
hH;i_("i(h
f]?&R c2C
public String getSFilePath() 06.8m;{N
{ w^nA/=;r
return sFilePath; `VGw5o
} z%+rI
[U^Cz{G
g;AW
public void setSFilePath(String value) d*k5h<jM
{ Rb:?%\=
sFilePath = value; knV*,
} c>/7E-T
'3Fb[md54
N:+EGmp
public String getSFileName() ax;<idC}
{ T5T[$%]6
return sFileName; \j wxW6>
} p*YV*Arv
DyZ6&*s$
0 .T5% _/
public void setSFileName(String value) :cXN Fu\C
{ MuzQz.C
sFileName = value; 7AGUi+!ICl
} wEI? 9
bvhV
~Cynw(
public int getNSplitter() e F}KOOfC
{ ;Q/1l=Bn
return nSplitter; OR+py.vK
} kqo4 v;r
:2vuc!Pu
j8^#698X
public void setNSplitter(int nCount) t*Z5{
{ b~)2`l
nSplitter = nCount; E|_8#xvb
} c`lL&*]
} /FPO'} 6i
!a!4^zqp
upeioC q
/* xy&*s\=:
**Utility.java 3tUn?;9B
*/ ]{+Y!tD
package NetFox; L %ifl:K
^4\0,>
e(b$LUV
public class Utility { r6aIW8
Z:x`][vg
b~YIaD[Z
public Utility() U-,s/VQ?
{ Z}>;@c
5^ubXA
3tkCmB
} ^x^(Rk}|
l)jP!k
//线程睡眠 f$dIPt(
public static void sleep(int nSecond) fWs*u[S
{ Q4]Od{[
try{ 4N7|LxNNl_
Thread.sleep(nSecond); t pxk8Ys
} ]EQ*!
catch(Exception e) o:4#AkS
{ '`W6U]7>
e.printStackTrace (); dShGIH?
} D,=#SBJ:Z
} UFj!7gX]
DeT$4c*:[
//日志 ,TB$D]u8
public static void log(String sMsg) Vr%ef:uVV
{ 1B~Z1w
System.err.println(sMsg); 4mX?PKvbn
} I};*O6D`
QJjk#*?,|
TK~KM
public static void log(int sMsg) Co=Bq{GY
{ u'DpZ
System.err.println(sMsg); 8=0I4\
} :LdPqFXj
} EUV8H}d5
&=:3/;c
ZYt<O
/* gMPp'^g]_
**TestMethod.java YZtd IG
*/ M&Ln'BC
package NetFox; n:1Ijh 1
H ="I=}
inK;n
public class TestMethod { tAY{+N]f
.EH1;/
I6@"y0I
public TestMethod() C'Y2kb
{ ///xx/weblogic60b2_win.exe <Kl$ek8
try{ zE/\2F$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8`]yp7ueS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kh#fUAt
SiteFileFetch fileFetch = new SiteFileFetch(bean); fl2XI=[v4
fileFetch.start(); Y ZuA"l Y
} \W= qqE]
catch(Exception e){e.printStackTrace ();} fWi/mK3c
V s=o@
?Drq!?3PDc
} Ve)BF1YG
M,bs`amz
vEGI
public static void main(String[] args) 9zIqSjos"
{ *BF[thB:a
new TestMethod(); L*vKIP<EMM
} gA@Zx%0j
} ]T2Nr[vu
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