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)); [rem,i+
} =*N(8j>y
for(int i=0;i<nEndPos.length-1;i++) <#i'3TUR
{ F"I@=R-n
nEndPos = nStartPos[i+1]; Jr zU-g
} :-n4!z"k
nEndPos[nEndPos.length-1] = nFileLength; u/WkqJvw#
} nAOId90wue
} g}7%3D
7="V7
#4?3OU#
//启动子线程 \WEC1+@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z_/03K$q
for(int i=0;i<nStartPos.length;i++) ]RJ2`xf
{ =s<QN*zJB0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c$TBHK;c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jkd8M;Jw
nStartPos,nEndPos,i); N0NMRU]zT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PT=%]o]
fileSplitterFetch.start(); NO)*UZ
} 4}`MV.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?e*vvu33!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~$<@:z{*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -i4gzak
nEndPos = " + nFileLength); R8_qZ;t:z
// fileSplitterFetch[nPos.length-1].start(); !+U.)u9 '
na>B{6
YjT #^AH
//等待子线程结束 |RdSrVB
//int count = 0; 2*N# %ZUX
//是否结束while循环 '=xl}v
boolean breakWhile = false; w1Kyd?~%]
~j_H2+!
dx#N)?
while(!bStop) $U1'n@/J
{ ^;e`ZtcI
write_nPos(); /on p<u
Utility.sleep(500); Fwtwf{9I
breakWhile = true; ~Km8-b(&
$vd._j&
a&JAF?k
for(int i=0;i<nStartPos.length;i++) 0nX5 $Kn
{ %"tf`,d~3
if(!fileSplitterFetch.bDownOver) gxiJ`.D=
{ sz5@=
breakWhile = false; ! JN@4
break; XT\;2etVL
} fw5AZvE6$
} mmi~A<
if(breakWhile) p<YO3@B+
break; tSjK=1"}
F+X3CB,f
QJ QQ-
//count++; a^N/N5-Z
//if(count>4) [Z1EjeX
// siteStop(); t{ 'QMX
} a v/=x
ie)Qsw@
1FuChd
System.err.println("文件下载结束！"); CBc}N(9
} !Lo{zTDW
catch(Exception e){e.printStackTrace ();} jhHb[je~{4
} *GA#.$n
WH!<Z=#c}
]l4\/EW6
//获得文件长度 3|C"F-'<
public long getFileSize() >?5`FC
{ oR~+s&c
int nFileLength = -1; kG{(Qi
try{ &{8 "- dw
URL url = new URL(siteInfoBean.getSSiteURL()); .!&YO/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E-RbFTVBA
httpConnection.setRequestProperty("User-Agent","NetFox"); 3B,nHU
pz(clTOD:
?C_%"!GR
int responseCode=httpConnection.getResponseCode(); 6rk/74gI,a
if(responseCode>=400) KxvT}"k
{ CNzK-,
processErrorCode(responseCode); #SL/Jr DZ
return -2; //-2 represent access is error 9F3`hJZRy>
} r`lgK2r\
zX3O_
8ciLzyrY*
String sHeader; UZV)A}
"?]5"lNC|
8s|r'
for(int i=1;;i++) ~_K
{ Dq\#:NnKvx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WvR}c
//Utility.log(in.readLine()); P0W%30Dh
sHeader=httpConnection.getHeaderFieldKey(i); X(bb1
if(sHeader!=null) &Zov9o:gx
{ 0DN:{dJz
if(sHeader.equals("Content-Length")) 3o/f#y
{ }3@`'i7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0<e7!M=U1
break; @NO&3m]
} 1wwhTek
} lp4sO#>`
else }D0j%~&"e
break; K^Xg^9
} $ \jly
} &98qAO]Z
catch(IOException e){e.printStackTrace ();} F M`pPx
catch(Exception e){e.printStackTrace ();} n6oVx5/
y:1?~R
qoOHWh&
Utility.log(nFileLength); Yd]f}5F
v%_sCg
cZ5[A T
return nFileLength; 2t_E\W7w+
} B^eea[
+1e*>jE
t#kmtJC
//保存下载信息（文件指针位置） 18a6i^7
private void write_nPos() -O2QzzE&
{ X~lOFH;}q
try{ sW[42A
output = new DataOutputStream(new FileOutputStream(tmpFile)); MTr _8tI
output.writeInt(nStartPos.length); b%AYYk)d?
for(int i=0;i<nStartPos.length;i++) &H*F
{ zm"&8/l
// output.writeLong(nPos); GlVq<RG*
output.writeLong(fileSplitterFetch.nStartPos); `,TPd ~#~
output.writeLong(fileSplitterFetch.nEndPos); 0ro)e~_@*
} 1`b?nX
output.close(); 75<E0O
} G.L4l|%W
catch(IOException e){e.printStackTrace ();} hd+JKh!u
catch(Exception e){e.printStackTrace ();} F/mD05{
} 8amtTM
d@`yRueWiV
#~(@Ka.eA0
//读取保存的下载信息（文件指针位置） TLi0*)}
private void read_nPos() ci,o'`Q
{ S# SA:>8s
try{ N+h|Ffnp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x%LWcT/
int nCount = input.readInt(); n_iq85
nStartPos = new long[nCount]; x}72jJe`
nEndPos = new long[nCount]; t,+p!"MRY
for(int i=0;i<nStartPos.length;i++) 7v1}8Uk
{ }**^g:
nStartPos = input.readLong(); I#9A\.pO
nEndPos = input.readLong(); UT"L5{c
} ""TRLs!:M
input.close(); 'v4AM@%u
} ~d28"p.7
catch(IOException e){e.printStackTrace ();} AlGD .K
catch(Exception e){e.printStackTrace ();} GMd81@7
} #~nI^ ggW
Ro?yCy:L'
0p![&O
private void processErrorCode(int nErrorCode) IgZX,4i=o
{ tWD*uAb
System.err.println("Error Code : " + nErrorCode); i9w xP i
} 7M5HIK6_
QTM+WD
;sb0,2YyP
//停止文件下载 URY%+u
public void siteStop() 8&H1w9NrX_
{ Xig%Q~oMp
bStop = true; >KC*xa"
for(int i=0;i<nStartPos.length;i++) bSBI[S
fileSplitterFetch.splitterStop(); ,1QU
9v0f4Pbxm
#kk_iS>8
} Nqz-Mr`
} I5PaY.i
//负责部分文件的抓取 5Gg`+o
**FileSplitterFetch.java -H{c@hl
*/ H`m|R
package NetFox; dc"Vc 3)
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DH@*Oz-
import java.io.*; $ 5
import java.net.*; Z5_MSPm
}Li24JK
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public class FileSplitterFetch extends Thread { @^/JNtbH!
;<MHDmD
[BmondOx
String sURL; //File URL `ffWV;P
long nStartPos; //File Snippet Start Position <"aPoGda
long nEndPos; //File Snippet End Position e$ E=n
int nThreadID; //Thread's ID [G4#DP\t>p
boolean bDownOver = false; //Downing is over v-4eN1OS
boolean bStop = false; //Stop identical -,3Ka:
FileAccessI fileAccessI = null; //File Access interface ZJ u\
^hTq~"
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v&p\r'w
{ $:F]O$A
this.sURL = sURL; *m2J$9q
this.nStartPos = nStart; F71.%p7C8"
this.nEndPos = nEnd; Bglh}_X
nThreadID = id; ytr~} M%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <dh7*M
} !)KX?i[Q
2A {k>TjQ
Z6 (;~"Em
public void run() (T!Q
{ L@9"6&
while(nStartPos < nEndPos && !bStop) bZ:w_z[3=
{ hZ5h(CQ?"#
Bu*ge~
+*~?JT
try{ i$"B
URL url = new URL(sURL); 3x.|g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V1;n5YL
httpConnection.setRequestProperty("User-Agent","NetFox"); a{,EX[~b
String sProperty = "bytes="+nStartPos+"-"; $nBzYRc"3
httpConnection.setRequestProperty("RANGE",sProperty); jja9:$#
Utility.log(sProperty); =)(sN"%
og!Uq]U/y
u%3Z +[
InputStream input = httpConnection.getInputStream(); \<a(@#E*~
//logResponseHead(httpConnection); qtD3<iWV
d|w%F=
sR ~1J4
byte[] b = new byte[1024]; =AGsW
int nRead; ci6j"nKci
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xsV(xk4
{ $yHlkd`Y
nStartPos += fileAccessI.write(b,0,nRead); s0qA8`Yu
//if(nThreadID == 1) 5}E8Tl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kMf]~EZ?
} )nTOIfP2
p8Ts5n
WwPfz<I
Utility.log("Thread " + nThreadID + " is over!"); gfFP-J3cN
bDownOver = true; ZSU;>&>%v
//nPos = fileAccessI.write (b,0,nRead); qbFzA i
} _hM3p
catch(Exception e){e.printStackTrace ();} +Q8Bin
} rG}o!I`z
} pkM_ @K
'$UlJDZ
=0MW+-
//打印回应的头信息 J$v0
public void logResponseHead(HttpURLConnection con) O5LB&s
{ }|(KI
for(int i=1;;i++) KPs5? X
{ jx+%X\zokA
String header=con.getHeaderFieldKey(i); $:t;WXc.<
if(header!=null) r,EIOcz:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )1Z*kY?f!
Utility.log(header+" : "+con.getHeaderField(header)); K.dgQ-vn
else GadQ \>
break; 9Psy$
} k#w[GL|T
} 1#&*xF"
AJI,>I,}}
w`UB_h#Bl
public void splitterStop() yo#&>W
{ 5NZob<<
bStop = true; oZA?}#DRl
} Yvcd(2
ry/AF
;SEH|_/
} 9pb4!=g*
d@8=%x:
9axJ2J'g
/* Y\Odj~Mj
**FileAccess.java ZYos.ay
*//文件访问(定位，写) q1;}~}W;z4
package NetFox; 7^A;.x
import java.io.*; Wt"fn&R}
3tMs613
S ])Ap'E
public class FileAccessI implements Serializable{ BHy#g>KUF
6HW<E~G'6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3U!\5Nsby
RandomAccessFile oSavedFile; 7q<I7Wt
long nPos; QU2\gAM
np}F [v
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public FileAccessI() throws IOException !=;^Grv>
{ KDhr.P.~
this("",0); w*Vf{[a'
} !?`5r)K
;\DXRKR
R%Gh4y\nF
public FileAccessI(String sName,long nPos) throws IOException k-@CcrepF
{ x00"d$!
oSavedFile = new RandomAccessFile(sName,"rw"); Xm8 1axyf
this.nPos = nPos; )q&=x2`
oSavedFile.seek(nPos); k6_RJ8I
} J@54B
[ Lt1OdGl
C\Qor3];
public synchronized int write(byte[] b,int nStart,int nLen) <03@cs
{ ~+d?d6*c
int n = -1; f^@`[MJj1C
try{ O,>1GKw"\
oSavedFile.write(b,nStart,nLen); *A':^vgk
n = nLen; In#V1[io
} |kyxa2F{
catch(IOException e) awQf$
{ :?2+'+%'
e.printStackTrace (); (.-3q;)6
} J?&lpsB3_l
al$G OMi
ER~m &JI
return n; QkBT,c
} {|c <8
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3U9]&7^
} Gnop
^o}!=aMr
R| [mp%Q
/* i% 19|an
**SiteInfoBean.java xwhH_[
*/ -} \g[|
package NetFox; /~)vma1<
p8o ~
-e_IDE
public class SiteInfoBean { gO_{(\w*
xa#0y
Q]9H9?}N?
private String sSiteURL; //Site's URL xq+$Q:f
private String sFilePath; //Saved File's Path Y0fX\6=h
private String sFileName; //Saved File's Name "v@$CR9<T
private int nSplitter; //Count of Splited Downloading File ]S4TX
ac%%*HN,
,R]hNjs-{
public SiteInfoBean() 9AK<<Mge.
{//nSplitter的缺省值为5 2mN>7Tj:
//default value of nSplitter is 5 =Bo(*%
this("","","",5); Y+75}]B
} w|!>>W6J
_Bm/v^(
flDe*F^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4^vEMq8lB
{ Se/VOzzg
sSiteURL= sURL; roT$dL P)w
sFilePath = sPath; F!OVx<
sFileName = sName; >F+Mu-^
this.nSplitter = nSpiltter; a]XQM$T$
~`)`Ip
)u?pqFH
} 1CK}XLdr
m"*j J.MX
!N:!x[5
public String getSSiteURL() M&o@~z0
{ UUi@ U
return sSiteURL; #12
} Nr)v!z~y
5W_u|z+/g
={,\6a|]:
public void setSSiteURL(String value) PhL}V|W>
{ 9[K".VeT]
sSiteURL = value; I@IZ1 /J,r
} 4#Wczk-b
U, _nEx
>MD['=J[d
public String getSFilePath() LdxrS5
{ R{Q*"sf
return sFilePath; nI4Kuz`dF
} x~p8Mcv
:ad
vW,dJ[N6jm
public void setSFilePath(String value) 88(h`RGMh
{ *y +T(73
sFilePath = value; 3\_ae2GW
} 8q9HQ4dsL
L1=+x^WQ
NH&/=
public String getSFileName() i}teY{pyc
{ 8|kr|l
return sFileName; /RD@ [ 8
} n,D~ whZx
GPBp.$q+B
IB9[Lx
public void setSFileName(String value) 'p<lfT
{ sq `f?tA?
sFileName = value; VN!`@Ci/
} i#Tm] ++
?+#|h;M8
_IzJxAcJ
public int getNSplitter() *J[3f]PBmR
{ xs+pCK|
return nSplitter; zbQ-l1E
} Q72}V9I9
533n z8&9@
x'IVP[xh`A
public void setNSplitter(int nCount) 69#mj*p@+
{ hBb&-/
nSplitter = nCount; V1y"
} B*=m%NXf
} _}MO.&Y
zN}1Qh
HJ4T! `'d
/* 8!8 yA
**Utility.java yB][ 3?lv
*/ .m--#r
package NetFox; /.PjHTM<
)P&>Tc?;z
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public class Utility { <1")JDW
u!kC+0Y
<}e2\x
public Utility() mqw5\7s?
{ 2.''Nt6|
PL+r*M%ll
l!r2[T]I@7
} yGGQ;!/
tJ:]ne
//线程睡眠 <'s_3AC
public static void sleep(int nSecond) >`\f,yql6
{ e,j2#wjor
try{ "J51\8G@@
Thread.sleep(nSecond); ]J<2a`IK!
} z4qw*. 5
catch(Exception e) }^T7S2_Qy
{ |>w>}w`~
e.printStackTrace (); +{b!,D3sa*
} m}t.E
} 4k}3^.#
.I~#o$6
//日志 FE}!I
public static void log(String sMsg) jg2UX
{ %BdQ.\4DS
System.err.println(sMsg); ;rBd_
} G)ppkH`qj
}b$?t7Q)
"EA6RFRD
public static void log(int sMsg) }>)e~\Tdzb
{ +sN'Y/-
System.err.println(sMsg); qG=?+em
} 5|T[:m
} .Vohd@s9l
2Fi~GY_
N^G $:GC
/* i=m5M]Ef
**TestMethod.java + F{hFuHV
*/ 0F"W~OQ6
package NetFox; " Bz\<e&u
Vrwy+o>:X
uL\b*rI
public class TestMethod { YY!Lv:.7>
*u?QO4>
#3b_#+,
public TestMethod() :K:oH}4oh
{ ///xx/weblogic60b2_win.exe {P'_s]B)
try{ JbV\eE#KrC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .G ^-.p
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s} I8:ufT
SiteFileFetch fileFetch = new SiteFileFetch(bean); *En29N#a{
fileFetch.start(); F&tU^(7<
} J^!2F}:
catch(Exception e){e.printStackTrace ();} *3uBS2Ld
>i6sJ)2?>
4AIo,{(
} q <, b
TFfV?rBI
d8)ps,
public static void main(String[] args) {V8yJ{.G
{ #9(0.!v
new TestMethod(); )S:,q3gxJ
} _u[2R=h
} Rm&^[mv
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