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)); svb7-.!
} X(rXRP#
for(int i=0;i<nEndPos.length-1;i++) r>TOJVT&]
{ 9F?-zn;2s
nEndPos = nStartPos[i+1]; :@ VCKq!
} ,S(s
nEndPos[nEndPos.length-1] = nFileLength; >goHQ30:
} OLm@-I*
} n;$u%2t2
:N"&o(^
.:B>xg~2
//启动子线程 );6f8H@G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r<Cr)%z!
for(int i=0;i<nStartPos.length;i++) AI#.+PrC{/
{ `wU['{=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _nEVmz!zg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;134$7!Y
nStartPos,nEndPos,i); \=mLL|a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +zq"dj_
fileSplitterFetch.start(); 3S2Alx!6
} (Z[c7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZH8w^}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Il(o[Q>jJ3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 96QY0
nEndPos = " + nFileLength); #62ThH~
// fileSplitterFetch[nPos.length-1].start(); o?t H[
N:k>V4oE
F4WX$;1
//等待子线程结束 V45adDiZ
//int count = 0; @G=7A;-pv0
//是否结束while循环 G$&jP:2q
boolean breakWhile = false; \[.qN
Az8ZA~Op=
QV:> x#=V
while(!bStop) "::2]3e
{ 6NhGTLI
write_nPos(); %dq%+yw{%m
Utility.sleep(500); F;h^o!W7r
breakWhile = true; B)1(
un -h%-e|
Ql l{;A
for(int i=0;i<nStartPos.length;i++) VKX|0~
{ x=Oy 6"
if(!fileSplitterFetch.bDownOver) D1v0`od'
{ "J2q|@.
breakWhile = false; 5B2p_$W#
break; jgG9?w)|u
} 9#&H'mG
} GiEt;8
if(breakWhile) W} H~ka
break; =BE!
JoiGuZd>
]&q<O0^'
//count++; \4G9YK-N>
//if(count>4) (l-=/6-
// siteStop(); Zl3e=sg=
} ~yw]<{?
~LV]cX2J(
>dm9YfQ
System.err.println("文件下载结束！"); ss-6b^
} PlLt^q.z[
catch(Exception e){e.printStackTrace ();} X#JUorGp
} 0'$67pY
lN,a+S/'
r hucBm
//获得文件长度 Og1vD5a
public long getFileSize() $ B&ZnZ?
{ F`x_W;\
int nFileLength = -1; <f8j^
try{ z |~+0
URL url = new URL(siteInfoBean.getSSiteURL()); ~M} K]Li
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h4|}BGO
httpConnection.setRequestProperty("User-Agent","NetFox"); K[OOI~"C
M|%bxG^l
nQ+5jGP1
int responseCode=httpConnection.getResponseCode(); FjtS
if(responseCode>=400) jaKW[@<
{ x< 2]UB`
processErrorCode(responseCode); R<6y7?]bZ
return -2; //-2 represent access is error Qg(;>ops
} M."/"hV`-
([>__c/Nd
{4Kvr4)4
String sHeader; .<z7$lz\
2(l0Lq*
"B (?|r%
for(int i=1;;i++) 3.BUWMD
{ 7]T(=gg /
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); js <Up/1
//Utility.log(in.readLine()); @_-,Q5
sHeader=httpConnection.getHeaderFieldKey(i); >Jx=k"Kv+
if(sHeader!=null) =d^hiR!GN
{ \OFmd!Cz
if(sHeader.equals("Content-Length")) zm5PlG
{ ,-E'059
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Komdz/g
break; }s<;YC
} ?z l<"u
} -wV2 79^b
else ov,s]g83
break; UhS:tT]7
} *#Ia8^z=p
} m+s*Io{Ip
catch(IOException e){e.printStackTrace ();} 63Gq5dF
catch(Exception e){e.printStackTrace ();} +ynhN\S$/
wyB]!4yy,
eQ#i.%
Utility.log(nFileLength); >L4F'#I
8&"Jlz |
l$9k:#\FD
return nFileLength; !0Nf`iCQ(
} u$[8Zmgzz
GEf=A.WAfw
v:/!OvLe
//保存下载信息（文件指针位置） X coPkW
private void write_nPos() Q> y!
{ _1G/qHf^S
try{ ]7W!f 2@
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ru*gbv,U
output.writeInt(nStartPos.length); Pm)*zdZ8
for(int i=0;i<nStartPos.length;i++) 87l*Y|osP
{ SQ[D2v
// output.writeLong(nPos); mKO~`Wq%@
output.writeLong(fileSplitterFetch.nStartPos); [5p9p1@u{C
output.writeLong(fileSplitterFetch.nEndPos); j0{`7n
} !Ea!"}
output.close(); -;_"Y]#
} 1#_pj eG
catch(IOException e){e.printStackTrace ();} 2h51zG#qd
catch(Exception e){e.printStackTrace ();} sa o&
} h>GbJ/^
T{+a48,;
~<VxtcEBz
//读取保存的下载信息（文件指针位置） i]k)wr(
private void read_nPos() /}U)|6-B
{ H6 x
try{ T&pCLvkz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W)Y`8&,
int nCount = input.readInt(); aXVldt'
nStartPos = new long[nCount]; WcKDerc
nEndPos = new long[nCount]; \z!lw
for(int i=0;i<nStartPos.length;i++) `IwZVz
{ Ii[U%
nStartPos = input.readLong(); ;u'VR}4ph
nEndPos = input.readLong(); ^\O*e)#*
} Y"8@\73(R
input.close(); MjC<N[WO>N
} TCyev[(
catch(IOException e){e.printStackTrace ();} _yN5sLLyb
catch(Exception e){e.printStackTrace ();} $aJay]F
} ZXYyG`3+
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a}NB6E)-
private void processErrorCode(int nErrorCode) !vu-`u~86
{ Kj @<$ChZw
System.err.println("Error Code : " + nErrorCode); Oz-/0;1n
} V9"R8*@-
h?n?3x!(
_%2ukuJ `
//停止文件下载 &57~i=A 3
public void siteStop() R)Mkt8v
{ O[MFp
bStop = true; RNB&!NC
for(int i=0;i<nStartPos.length;i++) }9\6!GY0
fileSplitterFetch.splitterStop(); nN<,rN{:
dE,E,tv
7!jb
} |Ol29C$@|
} ^|Fy!kp
//负责部分文件的抓取 _dk[k@5W{'
**FileSplitterFetch.java Pa d)|
*/ vf.MSk?~ar
package NetFox; Y3[KS;_fr9
i3|xdYe$
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import java.io.*; '1b8>L
import java.net.*; Bcv{Y\x;ko
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public class FileSplitterFetch extends Thread { VZcW 3/Y
`(?c4oq,c>
l]zQSXip
String sURL; //File URL L1!~T+%uQ
long nStartPos; //File Snippet Start Position +jB;
long nEndPos; //File Snippet End Position _w?!Mu
int nThreadID; //Thread's ID bv]SR_Tiq
boolean bDownOver = false; //Downing is over nrev!h
boolean bStop = false; //Stop identical aB;f*x
FileAccessI fileAccessI = null; //File Access interface s1cu5eCt
\w1XOm [)
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eJ45:]_%I@
{ N(4y}-w$
this.sURL = sURL; }gXhN"
this.nStartPos = nStart; L{jx'[C
this.nEndPos = nEnd; wMCg`rk
nThreadID = id; &\6},JN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 aeN #<M&$<
} 9Xg7=(#
]}b
tTTHQ7o*BD
public void run() |X>'W"Mn
{ {u y^Bui}
while(nStartPos < nEndPos && !bStop) b?`2LAgn
{ =6ru%.8U,
1gBLJ0q
$dI mA
try{ &UnhYG{A
URL url = new URL(sURL); [5IbR9_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fNAW4I I}
httpConnection.setRequestProperty("User-Agent","NetFox"); $[`rY D/.
String sProperty = "bytes="+nStartPos+"-"; F%p DF\
httpConnection.setRequestProperty("RANGE",sProperty); ["&{^
Utility.log(sProperty); /Q7q2Ne^*
aG;F=e
H:hM(m0?q
InputStream input = httpConnection.getInputStream(); w`8H=Hf
//logResponseHead(httpConnection); -V4{tIQY
P]^OSPRg
!Q~>)$Cf^
byte[] b = new byte[1024]; D['J4B
int nRead; )s:kQ~+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ua|iAD1
{ :X}SuM?c
nStartPos += fileAccessI.write(b,0,nRead); IYq#|^)5+
//if(nThreadID == 1) =C,DR4xh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U{ 0~&
} a"YVr'|
&Cj~D$kDEu
P,m+^,
Utility.log("Thread " + nThreadID + " is over!"); 5L2j,]
bDownOver = true; I^f|U
//nPos = fileAccessI.write (b,0,nRead); {"~[F2qR
} K:<Viz
catch(Exception e){e.printStackTrace ();} z6J12tu
} K!ogpd&X&
} $#n9C79Z@
IxUj(l1Fm
oh$"?N7n1
//打印回应的头信息 :^`j:B
public void logResponseHead(HttpURLConnection con) n6Uh%rO7S|
{ c3l(,5DtH
for(int i=1;;i++) ,sc#l<v
{ xV+\R/)x
String header=con.getHeaderFieldKey(i); ?K pDEH~\
if(header!=null) u{=h%d/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +Eb-|dM
Utility.log(header+" : "+con.getHeaderField(header)); *LBF+L^C%
else nkPlfH
break; \9p.I?=
} [I%eRo[
} W^^0Rh_
%fS1gSfh
".|8(Y
public void splitterStop() 5|eX@?QF58
{ J&'*N:d
bStop = true; m[y~-n
} .{ILeG
->51t
1WqCezI
} -a_qZ7
bQI :N
]7k:3"wH
/* ~u1~%
**FileAccess.java <Tgubv+J
*//文件访问(定位，写) uZ_?x~V/
package NetFox; H74'I}
import java.io.*; <?KgzIq2
cu5}(
l[5** ?#
public class FileAccessI implements Serializable{ <astIu Au
Z)xcxSo
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 : ^}!"4{
RandomAccessFile oSavedFile; Y{e,I-"{
long nPos; sV5k@1Y
[V?HK_~
lrHN6:x(Y4
public FileAccessI() throws IOException GNmP_N
{ EmUt/]
this("",0); ]g9SUFM
} q'H6oD`
LC=M{\
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public FileAccessI(String sName,long nPos) throws IOException 3`SH-"{j%
{ %jj-\Gz!
oSavedFile = new RandomAccessFile(sName,"rw"); o-_,l J7o^
this.nPos = nPos; *$VeR(QN
oSavedFile.seek(nPos); '.pGkXyQ
} ]5*H/8Ke7
-ys/I,}<
#gWok'ZcR
public synchronized int write(byte[] b,int nStart,int nLen) t4;gY298
{ ={o4lFe3v(
int n = -1; {c?{M.R
try{ ^|h_[>
oSavedFile.write(b,nStart,nLen); 2.);OFk+
n = nLen; &-NGVPk81`
} ZI$P Qz2i
catch(IOException e) X0ugnQ6
{ S]fkA6v
e.printStackTrace (); }3Ke
} VrT-6r'Y
(]mBAQ#hw
JM0+-,dl[
return n; Z[z" v
} c+ZdfdR
_z]v;Q
wDiq~!
} 0#yH<h$
?^-fivzS>
h^IizrqU
/* Qt'3v"S>)
**SiteInfoBean.java Tp~Qg{%Og
*/ Gl{2"!mt=
package NetFox; &u"mFweS
z/5TYv)S
*pS3xit~
public class SiteInfoBean { %y>*9$<pXe
'dQGb-<_<
$i8oLSRV
private String sSiteURL; //Site's URL %|/\Qu
private String sFilePath; //Saved File's Path ""V\hHdp
private String sFileName; //Saved File's Name :&$v.#
private int nSplitter; //Count of Splited Downloading File I`@>v%0
H_Hr=_8}-
}|=Fnyj
public SiteInfoBean() K43`$
{//nSplitter的缺省值为5 S9b=?? M)
//default value of nSplitter is 5 rwwyYIlEg
this("","","",5); Q-s5-&h(
} h>xB"E|.
z:O:g?A
b4KNIP7E
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0lqh;/
{ l'!_km0{d
sSiteURL= sURL; %dmQmO,
sFilePath = sPath; XI ><;#
sFileName = sName; Bz,Xg-k+
this.nSplitter = nSpiltter; Y>nQ<
4|jPr J
4rCw#mVtB
} :=quCzG
Y.52`s6F
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public String getSSiteURL() |t$%kpp
{ [8DPZU@
return sSiteURL; vls+E o]
} b\NY!)B
bWCtRli}
#'#@H
public void setSSiteURL(String value) *gwo.s
{ X"f]
sSiteURL = value; vvG*DGL)qL
} Kx;la
$G/p[JG6-
{>ghX_m|
public String getSFilePath() FVOPC:}bj
{ l~1l~Gx_&n
return sFilePath; =jG."o
} )ZZ6 (O
K[V#Pj9
|hvclEu,
public void setSFilePath(String value) xf:|lQf
{ tOQnxKzu
sFilePath = value; /I`-
} >IKIe
6SAYe%e
zP!j {y4w
public String getSFileName() dHn,;Vv^6
{ R C!~eJG!
return sFileName; $U^ Ms!'L
} V1,4M_Z
xiC.M6/
@&Af[X4s
public void setSFileName(String value) ){tTB
{ gHH[QLD=I
sFileName = value; IV`+B<3
} )\izL]=!t
@zsqjm
_^0UK|[
public int getNSplitter() y&F&Z3t
{ PC?XE8o
return nSplitter; DnB :~&Dw
} Qyj:!-o
0bQ"s*K
@7?L+.r$9
public void setNSplitter(int nCount) nG| NRp
{ |)ALJJ=+
nSplitter = nCount; ge&!GO
} v?q)E%5j
} p"Di;3!y!
f F9=zrW
Is ( Ji
/* ^"J)^3j<
**Utility.java :RXzqC
*/ Lnltt86
package NetFox; 9iK%@k
5.U|CL
0*/[z~Z-1
public class Utility { QyEoWKu;
pc](
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public Utility() $)jf
{ cD<5~`l
Z~g7^,-t
#t&L}=G{%
} ]n4G]ybK%
5mI}IS|@
//线程睡眠 5&Le?-/\
public static void sleep(int nSecond) y>JSo9[@
{ #<R6!"TNoz
try{ @aWd0e]
Thread.sleep(nSecond); 8SO(pw9
} FlLk.+!t
catch(Exception e) t\,XG
{ $_W kI^
e.printStackTrace (); x?G"58
} K|wB0TiXP
} OGnuBK
%Wg8dy|
//日志 WP?AQD
public static void log(String sMsg) 1n>(CwLG"
{ Wtj*Z.=:
System.err.println(sMsg); TDW\n
} v6'k`HnK
@VKN6yHH
B d?{ldg
public static void log(int sMsg) 3TnrPO1E
{ o;{BI Q1
System.err.println(sMsg); EpH\;25u
} n4Q ^
} yH',vC.
Sk%*Zo{|
6F3FcUL
/* p']oy;t
**TestMethod.java qbD[<T
*/ IFW"SfdZk
package NetFox; :sJQ r._L
$36.*s m
pn aSOyR
public class TestMethod { /9@VnM
@A8@j%CK1
j4]y(AA
public TestMethod() Q;eY]l8
{ ///xx/weblogic60b2_win.exe "|d# +C
try{ p2(Z(V7*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %v<BE tq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y3@5~4+
SiteFileFetch fileFetch = new SiteFileFetch(bean); _ v3VUm#
fileFetch.start(); Hus.Jfam
} ;^|:*
catch(Exception e){e.printStackTrace ();} /zIUYY
OCbwV7q:
}6 MoC0
} #-bz$w#*
|aS272'
G57c 8}\4
public static void main(String[] args) h~u|v[@{J
{ vW`[CEm^X
new TestMethod(); +E }q0GV
} $3^Cp_p6
} MW|:'D`
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