http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); jv7zvp
} &@Q3CCDS
for(int i=0;i<nEndPos.length-1;i++) 9UwDa`^
{ I;`V*/s8"
nEndPos = nStartPos[i+1]; j4l7Tx
} |fA[s7)
nEndPos[nEndPos.length-1] = nFileLength; g&za/F
} *= D$
} x?%vqg^r
!1l2KW<be
<ya3|ycnS
//启动子线程 ]juXm1)>W1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mkWIJH
for(int i=0;i<nStartPos.length;i++) YF"D;.
{ z XvWo6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '[HFIJ0K!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a@7we=!
nStartPos,nEndPos,i); XJlun l)(K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w7 QIKsI0
fileSplitterFetch.start(); `KL`^UqR
} }:BF3cH> 0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1S=I(n?E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +<iw|vr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %0]&o, w{
nEndPos = " + nFileLength); YF;8il{p
// fileSplitterFetch[nPos.length-1].start(); H"-p^liw
_W!g'HP-D
XGUF9arN
//等待子线程结束 1xx-}AIH#
//int count = 0; 1{,WY(,c
//是否结束while循环 MAR;k?d
boolean breakWhile = false; e8[*=&
Og,,s{\
KavRW.w
while(!bStop) [A3hrSw
{ -aO3/Ik[q
write_nPos(); $;@s
Utility.sleep(500); @^P=jXi<
breakWhile = true; lP@9%L
xLGAP-mx]
fkx 9I m4
for(int i=0;i<nStartPos.length;i++) 8n'C@#{WV
{ 6IvLr+I
if(!fileSplitterFetch.bDownOver) d8x$NW-s
{ aMHIOA%Kh
breakWhile = false; :H?p^d e
break; v5*SoUOF
} %;zA_Wg
} MjLyB^M
if(breakWhile) [szwPNQ_
break; xR%CS`0R
#cApk
;/YSQt)rc>
//count++; i=SX_#b^
//if(count>4) HDC`g
// siteStop(); ;id
} >`lf1x
M r@M~ -
8HWY]:|oh
System.err.println("文件下载结束！"); "#p)Z{v"!
} {)Gh~~57_W
catch(Exception e){e.printStackTrace ();} *rqih_j0
} RJg# A`
$y`|zK|G-
{UwJg
//获得文件长度 +]AE}UXZoh
public long getFileSize() '9b<r7\@
{ n ,H;PB
int nFileLength = -1; x-q er-
try{ I]} MK?
URL url = new URL(siteInfoBean.getSSiteURL()); Q}1PPi,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VNMhtwmK,
httpConnection.setRequestProperty("User-Agent","NetFox"); ?XeRL<n
mDo]5 i<
5[I9/4,
int responseCode=httpConnection.getResponseCode(); 8^HMK$
if(responseCode>=400) VGe/;&1h
{ lv{Qn~\y&
processErrorCode(responseCode); kWr*+3Xq
return -2; //-2 represent access is error fPspJug
} LtCkDnXk
_tYt<oB~%
Gd"lB*^Ht
String sHeader; O/Da8#S<
R*QL6t
%Uuhi&PA-l
for(int i=1;;i++) lMlXK4-
{ U-|gtND
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =`{!" 6a
//Utility.log(in.readLine()); Prr<:q
sHeader=httpConnection.getHeaderFieldKey(i); R`/nsou
if(sHeader!=null) & {B,m%G
{ XD*$$`+#
if(sHeader.equals("Content-Length")) 2< ^B]N
{ b$VdTpz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DGp'Xx_8
break; iT IW;Cv
} 0Wk}d(f
} z07!i@ue~
else 9t;aJFI
break; |QXW$
} '9i:b]Hru
} UD"e:O_
catch(IOException e){e.printStackTrace ();} Px)VDs=k
catch(Exception e){e.printStackTrace ();} [7L1y) I(
#B>Hq~ vrC
c~dX8+
Utility.log(nFileLength); .lRO;D
T w/CJg
U<o,`y[Tn
return nFileLength; t?{E_70W
} AnIENJ
d(R3![:
H@OYtPHGR
//保存下载信息（文件指针位置） KXYq|w
private void write_nPos() dZv-lMYBE
{ 1\_4# @')
try{ <gJ|Wee
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5GC{)#4
output.writeInt(nStartPos.length); ]Kil/Y
for(int i=0;i<nStartPos.length;i++) >|H=25N>;
{ yS lN|8d
// output.writeLong(nPos); C{+~x@
output.writeLong(fileSplitterFetch.nStartPos); Vk8:;Hj
output.writeLong(fileSplitterFetch.nEndPos); Rl<~:,D
} 9/q4]%`
output.close(); ;V`~'357%
} \tU91VIj
catch(IOException e){e.printStackTrace ();} :6Bk<
catch(Exception e){e.printStackTrace ();} eH79,!=2
} .2Gn)dZU
c tTbvXP
a&4>xZU #
//读取保存的下载信息（文件指针位置） aCy2.Qn
private void read_nPos() O*!+D-
{ 3E:wyf)i"
try{ T3+hxS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I6h{S}2
int nCount = input.readInt(); M HlP)'
nStartPos = new long[nCount]; c:hOQZ
nEndPos = new long[nCount]; )vhHlZ *+
for(int i=0;i<nStartPos.length;i++) 3mpEF<z
{ OZ$u&>916
nStartPos = input.readLong(); \O72PC+
nEndPos = input.readLong(); Kx$?IxZ
} ]p@7[8}
input.close(); cfa#a!Y4
} F(}d|z@@
catch(IOException e){e.printStackTrace ();} `N ;!=7y7Y
catch(Exception e){e.printStackTrace ();} [m!$01=
} Z'PL?;&+R
Vad(PS0
jHTaG%oh
private void processErrorCode(int nErrorCode) 86.!sQ8b
{ Q/-YLf.
System.err.println("Error Code : " + nErrorCode); q1`uS^3`
} Xq+7l5LP
'xvV;bi
Ui'~d(F
//停止文件下载 dV.)+X7<
public void siteStop() 1K4LEga`
{ H[fD >
bStop = true; j+PW9>Uh
for(int i=0;i<nStartPos.length;i++) NS mo(c>5
fileSplitterFetch.splitterStop(); L&q~5 9
mWta B>f
}0}J
} y/4 4((O
} W;OxH"eC
//负责部分文件的抓取 &h8+-
**FileSplitterFetch.java .@/5Ln
*/ :G$NQ*(z
package NetFox; IeZ}`$[H
X7Cou6r
z| i$eF;x3
import java.io.*; f+1)Ju~
import java.net.*; daY^{u3
4,wdIdSm4
ukzXQe;l1
public class FileSplitterFetch extends Thread { u.1u/o1"
/p?h@6h@y
64hr|v
String sURL; //File URL &.K=,+0_R/
long nStartPos; //File Snippet Start Position b;Q cBGwKT
long nEndPos; //File Snippet End Position #oJ9BgDry
int nThreadID; //Thread's ID \Vr(P>
boolean bDownOver = false; //Downing is over J:5%ff~r\
boolean bStop = false; //Stop identical }NiJDs
FileAccessI fileAccessI = null; //File Access interface JY_+p9KfyQ
ATPc~f
5 S7\m5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gj$gqO`B
{ ]C}z3hhk
this.sURL = sURL; @1^iWM j
this.nStartPos = nStart; &&Vz=6N
this.nEndPos = nEnd; ){L`hQ*=w
nThreadID = id; LtXFGPQf
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^mkplp a
} {*yhiE,
rR^VW^|f
$ [M8G
public void run() m80QMosp
{ .ie\3q)
while(nStartPos < nEndPos && !bStop) tg7%@SI5^-
{ A)/_:
3K_J"B*7
,4)zn6tC
try{ Ip|~j} }
URL url = new URL(sURL); l)4KX{Rz{A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }BzV<8F
httpConnection.setRequestProperty("User-Agent","NetFox"); :-69,e
String sProperty = "bytes="+nStartPos+"-"; s1?N&t8c
httpConnection.setRequestProperty("RANGE",sProperty); Zb^0EbV
Utility.log(sProperty); VNp[J'a>VZ
|Q@4F&k
'[I?G6
InputStream input = httpConnection.getInputStream(); Gh>Rt=Qu%
//logResponseHead(httpConnection); UQ}[2x(Kb
J)"2^?!&B
x32hO;
byte[] b = new byte[1024]; qm{(.b^
int nRead; to|O]h2*U2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [?Cv^t${+
{ v1oq[+
nStartPos += fileAccessI.write(b,0,nRead); !NuiVC]
//if(nThreadID == 1) xVfAlN37(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @/9#Z4&d0
} P\pHos
$^?Mip
*%=BcV+,
Utility.log("Thread " + nThreadID + " is over!"); g=XvqD<
bDownOver = true; +vIpt{733
//nPos = fileAccessI.write (b,0,nRead); o:W>7~$jr=
} ^Vso`(Ss
catch(Exception e){e.printStackTrace ();} M ~zA
} "v@Y[QI
} PzMJ^H{
%JF^@\E!|
ePv3M&\J
//打印回应的头信息 O2g9<H
public void logResponseHead(HttpURLConnection con) SR!EQ<
{ [uU"=H|
for(int i=1;;i++) &kUEnwQ-
{ $P&{DOiKS
String header=con.getHeaderFieldKey(i); ' ^E7T'v%
if(header!=null) Iv+JEuIi
//responseHeaders.put(header,httpConnection.getHeaderField(header)); f>!)y-7
Utility.log(header+" : "+con.getHeaderField(header)); hjf!FY*F
else ~"|MwR!0
break; ]9qY(m
} ;-sZaU;
} _N)/X|=~s
nsn
0)F.Y,L
public void splitterStop() Oy EOb>
{ u_H=Xm)9
bStop = true; !ij R
} W>TG!R 5
VaP9&tWXj
nilis-Bk_
} }?G([s56
?#s9@R1
qlSI|@CO
/* #dA9v7
**FileAccess.java *.%z
*//文件访问(定位，写) 5"sd
package NetFox; _D+pJ{@W
import java.io.*; Z9wKjxu+
aa2 vk)~
5PY4PT=G
public class FileAccessI implements Serializable{ mrmm@?
=hRo#]{(K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 HuT4OGBFpC
RandomAccessFile oSavedFile; H4B|c42
long nPos; 6v"WI@b4
W&~\@j]!D
i+qtL3
public FileAccessI() throws IOException eI,'7u4q
{ >}T}^F
this("",0); 'p FK+j
} rU4;yy*b
B4@1WZn<8
8Z|A'M
public FileAccessI(String sName,long nPos) throws IOException =jEVHIYt
{ o5B]?ekpq
oSavedFile = new RandomAccessFile(sName,"rw"); CCHGd&\Z
this.nPos = nPos; tm1#Lh0
oSavedFile.seek(nPos); Qli#=0{`
} |LV}kG(2
A)#w~X4
3AcS$.G
public synchronized int write(byte[] b,int nStart,int nLen) hbdB67,
{ ;fW`#aE
int n = -1; y(ceEV
try{ 15z(hzU?#
oSavedFile.write(b,nStart,nLen); |&"/u7^
n = nLen; 1%$t;R
} s6F0&L;N&
catch(IOException e) |2E:]wT}qg
{ .[r1Qz7G
e.printStackTrace (); YEa<zhO8
} ;il+C!6zpf
2FN E ;y(
,|g&v/WlC%
return n; X2|&\G9c
} {[4.<|26
oI5^.Dr FW
SoWMP2/
} eZ]>;5
6u'E}hAx|
rf^u&f
/* ?bH`
**SiteInfoBean.java mBxMDnh
*/ ]VR79l
package NetFox; "/G]M&
YSzC's[
!LQzf(s;
public class SiteInfoBean { DUSQh+C
x~i\*Ox^
v.ow`MO=;
private String sSiteURL; //Site's URL e,xJ%f
private String sFilePath; //Saved File's Path s{OV-H
private String sFileName; //Saved File's Name /2''EF';
private int nSplitter; //Count of Splited Downloading File L#?mPF
#)#J`s1R
Q;ZV`D/FA
public SiteInfoBean() B8unF=u
{//nSplitter的缺省值为5 Y[|9 +T
//default value of nSplitter is 5 ly69:TR7I
this("","","",5); B}P!WRNmln
} <`WDNi$Y
W9{i~.zo
-'}#j\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9@?|rje9
{ JC`;hY
sSiteURL= sURL; DxD\o+:r
sFilePath = sPath; L{GlDoFk
sFileName = sName; bxPJ5oT
this.nSplitter = nSpiltter; l*(L"]
z}iz~WZ
03AQB;.
} k{'<J(Hb
I]HLWF
tJ*/5k &
public String getSSiteURL() zJh!Q**
{ m^zD']
return sSiteURL; Bp5%&T k
} @=}NMoNH
t\]kVo)
I %sw(uoE
public void setSSiteURL(String value) 1;+77<
{ ]T(qk
sSiteURL = value; <(~Wg{
} \ KsKb0sM
I.Xbowl
A/&u/?*C
public String getSFilePath() NGRXNh+
{ ,Y#f0
return sFilePath; $C,`^n'
} yRDtPK"E-
)Jw$&%/{1
qG2P?DR
public void setSFilePath(String value) J0YNzC4
{ 4#t=%}
sFilePath = value; uKTYb#E7
} &|h9L'mr
dtjb(*x
ug'^$geM
public String getSFileName() >)Bv>HM
{ . Y$xNLoP[
return sFileName; Ef@)y&hn
} O;&5> W,Z
' QjJ^3A
YG5mzP<T
public void setSFileName(String value) @7;}6,)
{ -i_XP]b&
sFileName = value; f)V6VNW.3
} 16nU`TN
>z%WW&Z'
m;TekJXm
public int getNSplitter() &' y}L'
{ i=hA. y`
return nSplitter; +tG'
} @3U=kO(^+\
r^ '
K$s{e0 79
public void setNSplitter(int nCount) ?%D nIl>
{ ttt4h
nSplitter = nCount; /)dyAX(
} L.S/Mv
} zyt >(A1
>7cDfv"
nQg_1+
/* Hq?dqg'%~
**Utility.java ~EvGNnTL
*/ SP>&+5AydX
package NetFox; MOi1+`kwh
[L ' >
nyOmNvZf
public class Utility { Sogt?]HB$
jz>b>;
+=nWB=iCb
public Utility() $U)nrni
{ pTncx%!W5
)M"xCO3a
9ESV[
} R:f ,g2
k%aJ%(
//线程睡眠 hrXk7}9
public static void sleep(int nSecond) 5ci1ce
{ ;0uiO.
try{ a(G}<
Thread.sleep(nSecond); wLvM<p7OX
} M~+DxnJ=
catch(Exception e) $H&:R&Us
{ NK:! U
e.printStackTrace (); [N<rPHT
} 7*He 8G[W
} A5_r(Z-5
rfr]bq5
//日志 )HX(-"c
public static void log(String sMsg) 2h)Qz+|7
{ 'q@vTM'-
System.err.println(sMsg); FJT0lC
} )l`VE_(|
I<+:Ho=6
d"Zyc(Jk
public static void log(int sMsg) BPVOBL@
{ s%RG_"l
System.err.println(sMsg); dfZ`M^NU
} Q\btl/?
} gP |>gy#e
P?zaut
W! J@30
/* =hY/Yr%P
**TestMethod.java vUDMl Z
*/ *M$'dLn
package NetFox; !fjB oK+
eo.B0NZsF
'E\4/0 !
public class TestMethod { Iyb_5 UmpF
z<.?8bd
M5L/3qLh1
public TestMethod() l kyK
{ ///xx/weblogic60b2_win.exe [ugr<[6
try{ hML-zZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); '|<S`,'#hg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yhs:.h
SiteFileFetch fileFetch = new SiteFileFetch(bean); z\woTL6D]
fileFetch.start(); %E"Z &_3{
} IIAmx[ b
catch(Exception e){e.printStackTrace ();} T;V!>W37
qwO@>wQ}~
?0?3yD-!9
} -Zp BYX5e_
?nWzJ5w3
C7DwA/$D
public static void main(String[] args) tBX71d T
{ /'b7q y
new TestMethod(); \f)GW$`
} ^)(tO$S
} 0=K8 nxdx
点击下载更多相关资料