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)); !}4MN:r
} F35#dIs`&
for(int i=0;i<nEndPos.length-1;i++) ZKXo-~=>
{ %s&ChM?8F
nEndPos = nStartPos[i+1]; y|Ir._bt
} Bf$_XG3
nEndPos[nEndPos.length-1] = nFileLength; 1?| flK
} ;s~X
} &m[Qn!>i6
Y;)dct
#rY sj-2
//启动子线程 @fa@s-wb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?_ dIIQ
for(int i=0;i<nStartPos.length;i++) uaOKv.%
{ JMVNmq&0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @]![o %
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2CzaL,je[
nStartPos,nEndPos,i); .cR -V`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;/0 Q1-
fileSplitterFetch.start(); ;r6jx"i
} D)@YI.T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0v]?6wX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F {B\kq8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &<+ A((/i
nEndPos = " + nFileLength); %J8|zKT5t
// fileSplitterFetch[nPos.length-1].start(); 8kbY+W%n
^::EikpF%
<HRBMSR+
//等待子线程结束 i@][rdhT
//int count = 0; Hk7q{`:N
//是否结束while循环 i[ $0a4
boolean breakWhile = false; 8k^|G
n3lE,b
(oJ9k[(
while(!bStop) @A+RVg*=
{ x)UwV
write_nPos(); k"N(o(
Utility.sleep(500); 7t?*
breakWhile = true; WsFk:h'r
<F )_!0C
UYA_jpIP
for(int i=0;i<nStartPos.length;i++) 1.D-FPK
{ OgcHS?
if(!fileSplitterFetch.bDownOver) zd_HxYrN
{ 9=,uq;
breakWhile = false; ~w</!s
break; 2S8P}$mM
} >3gi yeJ
} xvNo(>
if(breakWhile) ]hud4i~
break; >23-
E`j-6:
zKFp5H1!%+
//count++; =H8 xSJLh
//if(count>4) z5*=MlZ)R.
// siteStop(); )s9',4$eK<
} h7X_S4p/Mg
y[@\j9Hq
\tyg(srw0
System.err.println("文件下载结束！"); 3K@@D B6
} )c/Fasfg[P
catch(Exception e){e.printStackTrace ();} zNSu
} K={qU[_O
Zc"B0_&?:7
( #Z`
//获得文件长度 P%Ay3cR+E
public long getFileSize() N:VX!w
{ sP'0Sl~NU
int nFileLength = -1; @^ ik[9^H
try{ |DF9cd^
URL url = new URL(siteInfoBean.getSSiteURL()); RQW6N??C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XA_FOw!cX
httpConnection.setRequestProperty("User-Agent","NetFox"); .w6eJ4]
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K:y^OAZfV
int responseCode=httpConnection.getResponseCode(); >cL{Ya}Rz
if(responseCode>=400) ]>i~6!@
{ Gi^Ha=?J%
processErrorCode(responseCode); Uf*EJ1Ei
return -2; //-2 represent access is error Z<b"`ty.
} \ u+xa{b|
t>UkE9=3\
ps:f=6m2
String sHeader; io4A>>W==/
>n.z)ZJ
o[6y+<'o
for(int i=1;;i++) *HM?YhR
{ ;SKh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &217l2X /
//Utility.log(in.readLine()); dpN@#w
sHeader=httpConnection.getHeaderFieldKey(i); f%qt)Ick
if(sHeader!=null) K%KZO`gO
{ cJ}QXuuUv
if(sHeader.equals("Content-Length")) M"^K0 .
{ +zOOdSFk.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GtI6[ :1t
break; Sj 3oV
} K3$` Kv>I
} eTE2J~\
else V`a+Hi<P\
break; s'a=_cN
} M7y|EB))
} Nofu7xiDw[
catch(IOException e){e.printStackTrace ();} f_r0})
catch(Exception e){e.printStackTrace ();} l`n5~Fs
ddpl Pzm#
f$xhb3Qn
Utility.log(nFileLength); d;suACW
,I*X)(
r:.uBc&_
return nFileLength; $@[)nvV\
} KjR4=9MD
.5hp0L}
] VG?+
//保存下载信息（文件指针位置） F$6?t.@J
private void write_nPos() 0o/B{|rv
{ f~gSJ<t4
try{ Sni=gZK
output = new DataOutputStream(new FileOutputStream(tmpFile)); c;V D}UD'
output.writeInt(nStartPos.length); 6Dzs?P
for(int i=0;i<nStartPos.length;i++) ~w.2-D
{ )bW<8f2
// output.writeLong(nPos); _`aR_%Gx
output.writeLong(fileSplitterFetch.nStartPos); i!~>\r\6\
output.writeLong(fileSplitterFetch.nEndPos); zHFTCL>"
} ?V+wjw
output.close(); D!l8l49hLu
} ep?:;98|t
catch(IOException e){e.printStackTrace ();} rF8 hr
catch(Exception e){e.printStackTrace ();} u6_jnZGB
} k:0P+d
Ow3a0cF[9
9s $PrF
//读取保存的下载信息（文件指针位置） {E~l>Z88
private void read_nPos() u5E/m
{ %|?1B$s0
try{ FE6C6dW{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p":@>v?
int nCount = input.readInt(); 6UB6;-
nStartPos = new long[nCount]; C"No5r'K3
nEndPos = new long[nCount]; D=9}|b/
for(int i=0;i<nStartPos.length;i++) wb+<a
{ \\iK'|5YG
nStartPos = input.readLong(); ~^7
nEndPos = input.readLong(); I=b'j5c
} .\4l'THn,0
input.close(); 9RcM$[~
} | XLFV
catch(IOException e){e.printStackTrace ();} 7kM4Ei
catch(Exception e){e.printStackTrace ();} XW:%vJu^`
} GiqBzV3"
^6&_|f
&:#A+4&
private void processErrorCode(int nErrorCode) /fC\K_<N
{ m9b(3
System.err.println("Error Code : " + nErrorCode); aZxO/b^j
} nr<.YeJ
cl2ze
TRCI\
//停止文件下载 VK$zq5D
public void siteStop() _M&{^d
{ +<B|qcT!
bStop = true; My0!=4Any
for(int i=0;i<nStartPos.length;i++) PuU*vs3
fileSplitterFetch.splitterStop(); #O><A&FrF`
6*V8k%H
#\0TxG5'QA
} ;6zPiaDQ
} )ZeLaaP
//负责部分文件的抓取 YkVRl [
**FileSplitterFetch.java AW62~*
*/ W`5a:"Vg
package NetFox; J[MVE4&
*H?t;,\
8eN%sm
import java.io.*; IF^[^^v+H
import java.net.*; M!-q}5';
!&\meS{
^YqbjL
public class FileSplitterFetch extends Thread { h9U+%=^O
v/ eB,p
S>(z\`1qm
String sURL; //File URL a&8l[xe1
long nStartPos; //File Snippet Start Position {q})kO
long nEndPos; //File Snippet End Position <TL])@da
int nThreadID; //Thread's ID VmMh+)UZ
boolean bDownOver = false; //Downing is over NuIT{3S
boolean bStop = false; //Stop identical TdNsyr}JG
FileAccessI fileAccessI = null; //File Access interface pAMo XJ`
*-{Omqw
6(,ItMbI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException OX`?<@6
{ nhp)yW
this.sURL = sURL; hJ<:-u+yk}
this.nStartPos = nStart; " S ?Km
this.nEndPos = nEnd; &^AzIfX}Gw
nThreadID = id; ]X/O IfdWe
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >s44
} Pu1GCr(
/j$$0F>s7
bGhhh/n
public void run() o.p+j
{ bb*c+XN0
while(nStartPos < nEndPos && !bStop) 8u4gx<;O
{ mi*:S%;h
5%EaX?0h+
aeLBaS
try{ =7*oC
URL url = new URL(sURL); @ysJt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PY[Sz=[
httpConnection.setRequestProperty("User-Agent","NetFox"); I|GV :D
String sProperty = "bytes="+nStartPos+"-"; u!hqq^1
httpConnection.setRequestProperty("RANGE",sProperty); s4^[3|Zrr0
Utility.log(sProperty); ?psOj%
W ]a7&S
Dh*~U:6$g
InputStream input = httpConnection.getInputStream(); ;4+qPWwq8W
//logResponseHead(httpConnection); Uh<H*o6e 9
mABwM$_
:_W0Af09
byte[] b = new byte[1024]; WiPM <'
int nRead; J R8 Z6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZE5-i@1
{ J"m%q\'
nStartPos += fileAccessI.write(b,0,nRead); qg) Af
//if(nThreadID == 1) }Bv30V2-(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3C E 39W
} &!3VqHQ`
wz*)L (pP
JKEXYE
Utility.log("Thread " + nThreadID + " is over!"); #n6FQ$l8m
bDownOver = true; f(w#LuW<
//nPos = fileAccessI.write (b,0,nRead); F[Guy7?O
} .j'@K+<45
catch(Exception e){e.printStackTrace ();} =R"Eb1
} i-K"9z|)
} 0jip::x
6Zl.Lh
$?CBX27AV
//打印回应的头信息 Ppi-skT
public void logResponseHead(HttpURLConnection con) URmAI8fq*M
{ ,6%hu|Y*
for(int i=1;;i++) YiY&;)w
{ E)rOlh7
String header=con.getHeaderFieldKey(i); Nv*E .|G
if(header!=null) <MWXew7b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c:`` Y:
Utility.log(header+" : "+con.getHeaderField(header)); ]iE.fQ?;J
else <?=mLOo=
break; _taHf %\4
} %Mb( c+7
} {YO%JTQ
} Khq
f>"!-3
public void splitterStop() >TQBRA;'
{ J6^Ct
bStop = true; G2[IO $
} XYxm8ee"j
NP<F==,
P!4{#'_}
} |)72E[lL
DS,FVh".|
f2w=ln
/* +=B}R
**FileAccess.java 9,EaN{GM
*//文件访问(定位，写) HC;I0&v>
package NetFox; M~{P',l*
import java.io.*; #@\NdW\
~b6<uRnM.
:hhE=A>X
public class FileAccessI implements Serializable{ >$S,>d_k`
"aCb;2Rs
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C +?@iMh
RandomAccessFile oSavedFile; YaJ{"'}
long nPos; >%p m"+h{
D`~{[cv)\
Dy{`">a
public FileAccessI() throws IOException :kiO
{ ng&EGM
this("",0); J"2ODB5"
} 7U[L\1zS
noUZ9M|hz
< 8 Y<w|Hh
public FileAccessI(String sName,long nPos) throws IOException )x:j5{>(
{ Z/05 wB
oSavedFile = new RandomAccessFile(sName,"rw"); 0iZ9a/v
this.nPos = nPos; o?O,nD 6
oSavedFile.seek(nPos); *"QE1Fum'
} } @fu~V/
k-ex<el)#
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public synchronized int write(byte[] b,int nStart,int nLen) `w=H'"Zv
{ (jE:Q2"
int n = -1; PD T\Q\J^X
try{ FqUt uN
oSavedFile.write(b,nStart,nLen); d,rEEc Y
n = nLen; v4>"p!_C
} .SV3<)
catch(IOException e) ,f0g|5yDf
{ ^RyTK|SQ
e.printStackTrace (); X>GY*XU
} ]|LaMMD
)>M@hIV5>
P"_}F
return n; 2l(j 4~g
} Q.2nUT`
#M^Yh?~%w
c)!s[oL
} U8$dG)PhA
`L*;58MA
5m7Ax]\
/* g#%FY1xp
**SiteInfoBean.java <d&)|W
*/ dlzamoS@AR
package NetFox; 2T%f~yQ^
Bpo68%dx89
"sx&8H"
public class SiteInfoBean { A}Dpw[Q2@8
N b[o6AX
eL?si!ZL^
private String sSiteURL; //Site's URL Ry S{@=si
private String sFilePath; //Saved File's Path ~d `4W<1a
private String sFileName; //Saved File's Name b-zX3R;
private int nSplitter; //Count of Splited Downloading File :@Dos'0Px
3 DHA^9<q
~tuFjj^
public SiteInfoBean() M>gZVB,eP>
{//nSplitter的缺省值为5 UBHQzc+,
//default value of nSplitter is 5 [IBk-opap
this("","","",5); JsEEAM:w
} >D4Ez
5g>kr<K
l4reG:uYG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9ufs6z
{ W*`6ero
sSiteURL= sURL; y]4`d
sFilePath = sPath; /(pChY>
sFileName = sName; K.1yncS^
this.nSplitter = nSpiltter; A;x^6>
mM{v>Em2K#
2vQ^519
} ,6Q-k4_
HWOH8q{f!
'\\Cpc_g
public String getSSiteURL() 'k Z1&_{
{ =T}uQ$X
return sSiteURL; t+J6P)=
} Z x%@wH~
: X|7l?{xW
{=7i}xY]T
public void setSSiteURL(String value) ?+=|{{l
{ NYvj?>[y
sSiteURL = value; 1u+(rVQN
} [V0h9!
3~xOO*`o
Rj`Y X0?+
public String getSFilePath() as!j0j%
{ 5305N!
return sFilePath; *S_Iza #&x
} z1s"C[W2T
j)qh>y)
~"Ki2'j)^]
public void setSFilePath(String value) n$l]+[>
{ F &}V65
sFilePath = value; !I_4GE,
} MV\zwH
??V["o T
wwn}enEz,x
public String getSFileName() qG]PUc>j
{ q:.BY}X9
return sFileName; Ngnjr7Q={T
} =>*N W9c
-1JHhRr]
q/?_djv
public void setSFileName(String value) C,hsr
{ oD\+ 5[x
sFileName = value; 0{F.DDiNT
} 'DQyB`V2y
Dm#k-y
HXI}f\6x
public int getNSplitter() >,3 3Jx
{ a~>h'}C>
return nSplitter; .vMi<U;
} .SN]hLV5
3(5Y-.aK}^
8F1!9W7
public void setNSplitter(int nCount) ? Q}{&J
{ [dMxr9M
nSplitter = nCount; BYU.ptiJJ
} mX^RSg9E}
} {IWb:p#I]
K>y+3HN[6
<!^Z|E
/* ez{&Y>n
**Utility.java =Frr#t!(w0
*/ cDg27xOUi
package NetFox; ny=iAZM>q
d%bL_I)
qv\yQ&pj
public class Utility { s8Oz^5p(
'! (`?
pG&.Ye]j
public Utility() 1 <+^$QL
{ l<0V0R(
*F0N'*
. {I7sUQ
} h 8s*FI
srL,9)OC
//线程睡眠 A7H=#L+C
public static void sleep(int nSecond) S[M$>
{ EX_&wep@1
try{ RS~oSoAE
Thread.sleep(nSecond); )1/O_N6C
} B_> Fd&
catch(Exception e) lV8Mr6m
{ J$0*K+m
e.printStackTrace (); I8y\D,
} zw?6E8$h
} U|=y&a2Rb
\T0`GpE
//日志 Y%3j>_\;
public static void log(String sMsg) ":OXs9Yg
{ M5]wU
System.err.println(sMsg); H,'c&
} Xma0k3;-
c!zu0\[Id
$\H>dm
public static void log(int sMsg) Ap/WgVw;
{ #ed]zI9O
System.err.println(sMsg); "LYob}_z
} Z,*VRuA
} N}\i!YUD
lG2){){j
V;$lgTs|'
/* ]Sh&8 #
**TestMethod.java Ex<loVIrP$
*/ <iMLM<J<w
package NetFox; ~34$D],D
B6BOy~B0
xed$z
public class TestMethod { V5=Injs*
"QMHY\C
gbvBgOp
public TestMethod() *fE5Z;!}
{ ///xx/weblogic60b2_win.exe `|gCbs95
try{ aD.A +es
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -Jb I7Le
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sviGS&J9h
SiteFileFetch fileFetch = new SiteFileFetch(bean); bp }~{]:b
fileFetch.start(); T+I|2HYqOj
} cng1k
catch(Exception e){e.printStackTrace ();} g%K3ah v
/Z^+K
dme_Ivt
} zDX-}t_'q
\hg12],#:@
xSw ^v6!2
public static void main(String[] args) T3\Q<
{ #fQStO
new TestMethod(); ;#AV~Y- s
} ;%Qu;FtC
} Hg<]5
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