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)); BJ(M2|VH
} 08{@rOr
for(int i=0;i<nEndPos.length-1;i++) Etm?'
{ g9F?z2^
nEndPos = nStartPos[i+1]; #`s"WnP9'!
} \l3h0R
nEndPos[nEndPos.length-1] = nFileLength; m#p'iU*va,
} N{>n$v}
} > Nr#O
Rf1x`wml
akQ7K
//启动子线程 }ad|g6i`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ovV'VcUs
for(int i=0;i<nStartPos.length;i++) RG`1en
{ =g|FT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =tY T8Q;al
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |Q>IrT
nStartPos,nEndPos,i); IE~ |iQ?-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >LuYHr
fileSplitterFetch.start(); #_lDss
} e>7i_4(C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T[j,UkgGo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u#SWj,X
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rrv%~giU
nEndPos = " + nFileLength); vfo~27T{(
// fileSplitterFetch[nPos.length-1].start(); rVsJ`+L
Af{"pzY
Rx}Gz$
//等待子线程结束 vr^qWn
//int count = 0; ,Y48[_ymm
//是否结束while循环 Du){rVY^d
boolean breakWhile = false; Lj;2\]
<0?W{3NqI
DlNX 3
while(!bStop) igAtRX%Qx
{ _J[P[(ab
write_nPos(); xkR0
Utility.sleep(500); GuL<Z1<c
breakWhile = true; >F&47Yn
Sa5G.^XI
)\^-2[;
for(int i=0;i<nStartPos.length;i++) `@s^(hc7i
{ X\F|Tk3_
if(!fileSplitterFetch.bDownOver) 5/z/>D;
{ =nHgDrA_
breakWhile = false; gPc=2
break; t&DEb_"De
} Ti&z1_u
} KY]C6kh
if(breakWhile) Om {'1
break; 9~YMyg(Z
O|UC ?]6
{FTqu.
//count++; !0E&@X:-
//if(count>4) WOf 4o
// siteStop(); 7J&4akT{9
} SK.: Q5:
pY$Q
<b<j=_3
System.err.println("文件下载结束！"); GowH]MO
} [PKR2UEe]
catch(Exception e){e.printStackTrace ();} dAe')N:KPI
} H 7 ^/q7
D|#E9OQzs
o%*xvH*A
//获得文件长度 6\S~P/PkE
public long getFileSize() 2VCI 1E
{ *HB-QIl
int nFileLength = -1; #LN`X8Wz'
try{ *4_Bd=5(U
URL url = new URL(siteInfoBean.getSSiteURL()); s(roJbJ_;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S`?!G&[!>
httpConnection.setRequestProperty("User-Agent","NetFox"); dGTsc/$
8e"gW >f
O<W_fx8_'
int responseCode=httpConnection.getResponseCode(); -s'-eQF J
if(responseCode>=400) ?Pc'C
{ pFz`}?c0
processErrorCode(responseCode); 8sK9G` k
return -2; //-2 represent access is error e<q?e}>?
} {cw /!B
q6X1P"%.
$xdy&
String sHeader; y L~W.H
gbagi+8s`%
dcWD(-
for(int i=1;;i++) jm r"D>
{ ##4HYQ%E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Mh 7DV
//Utility.log(in.readLine()); {T~#?v(
sHeader=httpConnection.getHeaderFieldKey(i); -RK- Fu<e
if(sHeader!=null) m<2M4u
{ BJo*'US-Q
if(sHeader.equals("Content-Length")) ?5 [=(\/.
{ W'u>#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vEz"xz1j!]
break; ib791
} xFg>SJ7]
} wo5
else ZWp(GC1NA
break; c-FcEW
} t.\dpBq
} i<g-+Qs
catch(IOException e){e.printStackTrace ();} %BB%pC
catch(Exception e){e.printStackTrace ();} ^D-/`d
w917N4$
|)/aGZ+
Utility.log(nFileLength); sds"%]rg
QoH6
@49S`
return nFileLength; KRKCD4
} &~U ]~;@
N_q|\S>t/
('p5:d
//保存下载信息（文件指针位置） P J[`|
private void write_nPos() R0
{ K@w{"7}
try{ 0NX,QD
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4tmAzD
output.writeInt(nStartPos.length); l0i^uMS
for(int i=0;i<nStartPos.length;i++) delu1r
{ g5r(>,vY
// output.writeLong(nPos); ! #2{hQRu
output.writeLong(fileSplitterFetch.nStartPos); K8Y=S12Ti
output.writeLong(fileSplitterFetch.nEndPos); uOdl*|T?
} c<$OA=n
output.close(); EI^C{$Y
} G[q$QB+
catch(IOException e){e.printStackTrace ();} `%WU8Yv
catch(Exception e){e.printStackTrace ();} cD'V>[h
} 2WYPO"q
fvxu#m=
:tv,]05t
//读取保存的下载信息（文件指针位置） C'}KTXiRW
private void read_nPos() W#3Q ^Z?
{ v^+Sh|z/
try{ Qv/=&_6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3I-MdApT
int nCount = input.readInt(); UN<]N76!
nStartPos = new long[nCount]; qPfQy
nEndPos = new long[nCount]; lQkQ9##*
for(int i=0;i<nStartPos.length;i++) 2x0<&Xy#P
{ hODWB&b
nStartPos = input.readLong(); 'Ne@e)s9
nEndPos = input.readLong(); 0}quG^%_
} aPbE;" f
input.close(); Q^txVUL
} dL )<% o
catch(IOException e){e.printStackTrace ();} l8#EM1g-
catch(Exception e){e.printStackTrace ();} ]f9Cx\d:k
} `$aZ0+
WbqWG^W
Czu\RXJR
private void processErrorCode(int nErrorCode) 8StgsM
{ _/5H l`
System.err.println("Error Code : " + nErrorCode); Pw!MS5=r
} Otm0(+YB7
-Wi` G
p|D/;Mk
//停止文件下载 9|CN8x-
public void siteStop() LOV)3{m
{ ZSd4z:/
bStop = true; Pce;r*9
for(int i=0;i<nStartPos.length;i++) i9][N5\$
fileSplitterFetch.splitterStop(); t"/q]G5
l$bu%SZ
#';:2Nyq
} xbYi.
} **G9H
//负责部分文件的抓取 {8,J@9NU
**FileSplitterFetch.java Y#$%iF
*/ B%+T2=&$7
package NetFox; IG9VdDj
~|xA4u5LG
yhA6i
import java.io.*; )+t0:GwP`:
import java.net.*; H-fX(9
3]3|
v9O~@v{=
public class FileSplitterFetch extends Thread { Q%mB|i|
':m,)G5&
ly3\e_z:G
String sURL; //File URL HYSIN^<oy
long nStartPos; //File Snippet Start Position tr}Loq\y
long nEndPos; //File Snippet End Position *CTlOy
int nThreadID; //Thread's ID (|1A?@sJ#h
boolean bDownOver = false; //Downing is over nq8C'Fo!6T
boolean bStop = false; //Stop identical 2Gaa(rJ5o
FileAccessI fileAccessI = null; //File Access interface 6]%sFy2
*U=s\
;&-k#PE]/H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'o>B'$
{ rK]Cr9WM
this.sURL = sURL; =CVBBuVy
this.nStartPos = nStart; }"!I[Ek> y
this.nEndPos = nEnd; q\p:X"j|
nThreadID = id; tQYM&6g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +@k+2?] FO
} RcU}}V
' x35=@
!s?nJ(p
public void run() I(7NQ8Hx
{ VYImI>.t{
while(nStartPos < nEndPos && !bStop) Ob`d
{ !AfHk|
@;?p&.W`D
Opc ZU{4b
try{ |kV*Jc k
URL url = new URL(sURL); q6`b26
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mahJSz(3
httpConnection.setRequestProperty("User-Agent","NetFox"); c?&X?<
String sProperty = "bytes="+nStartPos+"-"; s6.M\^
httpConnection.setRequestProperty("RANGE",sProperty); @Y<bwv
Utility.log(sProperty); ;{tj2m,
x%!s:LVX
f-G:uI_
InputStream input = httpConnection.getInputStream(); h2J/c#Qvh
//logResponseHead(httpConnection); 8~z~_TD6m@
6){]1h"
8MzVOF{"
byte[] b = new byte[1024]; )@Yf]qx+Y<
int nRead; mtmjZP(w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Y^}Z>
{ 3L}!RB
nStartPos += fileAccessI.write(b,0,nRead); `q*M4,
//if(nThreadID == 1) 64G[|" j D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (VEpVn3{
} \VyZ
"8^ Ch{G-
sAS:-wp
Utility.log("Thread " + nThreadID + " is over!"); z Q`jP$2
bDownOver = true; sjwo/+2
//nPos = fileAccessI.write (b,0,nRead); >$7v ;Q
} f"SD/]q-
catch(Exception e){e.printStackTrace ();} m\r@@!
} ^c4@(]v'G
} *><F'
?+W9az]+
VZymM<O
//打印回应的头信息 y8!4q
public void logResponseHead(HttpURLConnection con) ADP%QTdqFJ
{ Et/\xL
for(int i=1;;i++) @As[k2
{ c[4i9I3v
String header=con.getHeaderFieldKey(i); VE{3}S
if(header!=null) EGzzHIZ`!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (b~T]3Es
Utility.log(header+" : "+con.getHeaderField(header)); 6ZG+ZHUC&
else !1DKLQ
break; b TM{l.Aq3
} %GA"GYL9'
} evAMJ=
-Rd/Gx
#_J@-f7^
public void splitterStop() pg.ri64H<
{ >qjq=Ege
bStop = true; b8"?VS5-"
} LO khjHR
Ix!Iw[CNd
L>W'LNXCv
} n%C>E.Tq
NS%xTLow-
IE&!YP(U(
/* y7 3VFb
**FileAccess.java n}_JB>i~
*//文件访问(定位，写) ?Exv|e
package NetFox; B~JwHwIhA
import java.io.*; ~&8^9E a
_w/EP
A3no~)wZn
public class FileAccessI implements Serializable{ g-HN
UAFwi%@!-q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x:>wUhzZ
RandomAccessFile oSavedFile; E^lvbLh'
long nPos; Wm"4Ae:B
+ SFVv_n
I)cFG{~L
public FileAccessI() throws IOException f3&[#%
{ iZNts%Y]
this("",0); D 38$`j
} Y/>&0wj)d
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ujaGNg?,
public FileAccessI(String sName,long nPos) throws IOException !2A:"2Kys:
{ +!z{5:
oSavedFile = new RandomAccessFile(sName,"rw"); RIXMJ7e7
this.nPos = nPos; RHq/JD-
oSavedFile.seek(nPos); Z!@~>i
} *-q"3D`
Nq` C.&
P8>d6;o($
public synchronized int write(byte[] b,int nStart,int nLen) Nz+949X
{ rI>aAW'
int n = -1; 8lb%eb]U
try{ SAK!z!t
oSavedFile.write(b,nStart,nLen); ang~<
n = nLen; Xr2ou5zAn
} .DR<Te
catch(IOException e) %K`% *D
{ ~ ! 3I2
e.printStackTrace (); J'fQW<T4wU
} OQT;zqup
Fpa;^F
jm0- y%
return n; P%=#^T&`}
} '0uhD.|G
HA`@7I
`V"sOTb
} =%gRW5R%
W4e5Rb4~f"
RIE5KCrGB
/* iz?tu: \v&
**SiteInfoBean.java /yF QeE
*/ 2Sp=rI
package NetFox; CkD#/
;SaX;!`39+
Y&_&s7z
public class SiteInfoBean { NqEA4C
dBe`p5Z
oiyzHx
private String sSiteURL; //Site's URL Tp?y8r
private String sFilePath; //Saved File's Path x.zbD8l/9
private String sFileName; //Saved File's Name (v|}\?L
private int nSplitter; //Count of Splited Downloading File WxJf{=-
DrBUe'RH:M
_ozg_E
public SiteInfoBean() ?a8(azn
{//nSplitter的缺省值为5 ]Xf% ,iu
//default value of nSplitter is 5 @`Eg(
this("","","",5); XC "'Q+
} .YnFH$;$
:.d:9Z|_
\&3"<6xA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f=!VsR2o
{ MpqZH{:?G
sSiteURL= sURL; CI :`<PZ\-
sFilePath = sPath; t" 7yNs(I
sFileName = sName; ;VNMD 6H
this.nSplitter = nSpiltter; OhmQ,
7&"n`@(.!
}X_;X_\3;'
} T4 N~(Fi)
)aao[_ZS
VX+jadYdq
public String getSSiteURL() MJCzo |w
{ hL;8pE8
return sSiteURL; ""h)LUrl
} )a3J9a;ZS0
L%$|^T=%
f{i8w!O"~
public void setSSiteURL(String value) N, *m ,
{ a/U2xq{x
sSiteURL = value; PN<C=gAe
} bb`':3%
P<2+L|X?}
|vMpXiMxxT
public String getSFilePath() saAxGG
{ +:-57
return sFilePath; ^1x*lLf
} {}m PEd b
U{$1[,f
EVUq--)~
public void setSFilePath(String value) 3ZZV<SS
{ iQ6epg1wB
sFilePath = value; lz0TK)kuC
} TO*BH^5R
qdG~!h7j
h:)Ci!D;
public String getSFileName() [kzd(u
{ kWb2F7m
return sFileName; ;v~-'*0
} (NK9vW4F
t"lyvI[
p,<&zHb>K
public void setSFileName(String value) `)h6j)xiQ
{ jWO/ xX
sFileName = value; GK}'R=
} !W'Ui 9uX
~!d/8?!
y}K\%;`[a
public int getNSplitter() s(LT
{ ~i_Tw#}
return nSplitter; (j"(
} Rek -`ki5F
"ZHtR/;
\[>9UC%
public void setNSplitter(int nCount) %|l8f>3[
{ %q322->Z
nSplitter = nCount; hv$m4,0WB
} f8<o8*`7
} R%H$%cnj
1?Aga,~k:a
ph|ZG6:
/* Ei3zBS?J)
**Utility.java ia{c
*/ vNOH&ja-s
package NetFox; 0Hw-59MK
#W2[
Y'3}G<'%
public class Utility { asgF1?r
FNQX7O52
Gy Qm/I
public Utility() \#x}q'BC4
{ qxJQPz
9H]Lpi^OH
=}fd6ea(o
} @C-dG7U.P
uH^PQ
//线程睡眠 Hv<'dt$|
public static void sleep(int nSecond) `}no9$l~
{ XfzVcap
try{ PaCzr5!~f
Thread.sleep(nSecond); jSQ9.%4
} 5NXt$k5
catch(Exception e) ZDYJhJ.
{ Zz |MIGHm
e.printStackTrace (); Bl1Z4` 3
} rn:!dV[
} 6`"M
SnTDLa
//日志 ])#\_'fg
public static void log(String sMsg) %im#ww L%
{ ,rwuy[Q8
System.err.println(sMsg); w[Ep*-yeI
} xq-$\#O
=]Hs|{
}98>5%Uv
public static void log(int sMsg) agOk*wH5
{ D0]a\,aZ
System.err.println(sMsg); g#K'6VK{
} y466A]|
} i(wgB\9i4
o8FXqTUcs4
q cA`)j
/* qturd7
**TestMethod.java Y ZaP
*/ Y&r]lD
package NetFox; h#Ce_,o
Cw,D{
h:Ndzp{
public class TestMethod { ;<G<1+
;+I4&VieK
vV`|!5x
public TestMethod() C;\VO)]t
{ ///xx/weblogic60b2_win.exe Y5!b)vke
try{ cf[vf!vi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3@O0^v-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jV7&Y.$zF]
SiteFileFetch fileFetch = new SiteFileFetch(bean); JK~ m(oQ
fileFetch.start(); P-JfV7(O8
} {rkn q_;0
catch(Exception e){e.printStackTrace ();} WA.\*Nqze
kJ: 2;t=
ZAg;q#z j
} 3On JWuVfZ
q:HoKJv4
Ew^ @Aq
public static void main(String[] args) WY)^1Gb$ux
{ s"0b%0?A
new TestMethod(); o;-<|W>
} G\Q9IcJ0dY
} %XXkVK`
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