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)); Pa0tf:
} jY87NHg
for(int i=0;i<nEndPos.length-1;i++) s67$tlV
{ ;Qk*h'}f
nEndPos = nStartPos[i+1]; aJI>qk h?]
} Yfxc$ub
nEndPos[nEndPos.length-1] = nFileLength; 6M+~{9(S
} #3kR}Amow
} 2}~1poyi>
CM9+h;Zm
&>L\unS
//启动子线程 =2J+}ac
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jpm}EOq<%
for(int i=0;i<nStartPos.length;i++) Be8Gx
{ akJ{-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q}\,7l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .Zf#L'Rf
nStartPos,nEndPos,i); r;upJbSX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uW Q`
fileSplitterFetch.start(); wqA5GK>m2
} uZd)o AB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MSRIG-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CEqfsKrsxE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1hi^
nEndPos = " + nFileLength); \&ERSk2
// fileSplitterFetch[nPos.length-1].start(); @_N -> l
aH'^`]'_=
;bP7|
//等待子线程结束 |06J4H~k
//int count = 0; ;PG'em
//是否结束while循环 clG3t eC
boolean breakWhile = false; asPD>jc
Lm-}W "7
\ E[0KvN;O
while(!bStop) !Q#u i[0q
{ P,I3E?! j
write_nPos(); u`E_Q8
Utility.sleep(500); Q`r1pO
breakWhile = true; *J1pxZ^
*DDfdn
IGu*#>h
for(int i=0;i<nStartPos.length;i++) ,2&'8:B
{ RDzL@xCcn
if(!fileSplitterFetch.bDownOver) ``aoLQc`
{ >%Y.X38Z[
breakWhile = false; >s[}f6*2@
break; c{||l+B
} +1h^9Y'
} bTHJbpt*-
if(breakWhile) 1;ZEuO
break; ?em)om
nez5z:7F
g.F{yX]
//count++; bgYM
//if(count>4) ^Ud`2 OW;2
// siteStop(); tet
} t MA
,,fLK1
ELY$ ]^T
System.err.println("文件下载结束！"); JK,#dA#
} ,ZMYCl]
catch(Exception e){e.printStackTrace ();} w:z_EV!&
} r'xa'6&
-J? df
f4@Dn >BJ
//获得文件长度 z81I2?v[Jr
public long getFileSize() BtU,1`El5
{ r~t&;yRv
int nFileLength = -1; 4XX21<yn
try{ 4fP>;9[F
URL url = new URL(siteInfoBean.getSSiteURL()); r10)1`[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2<u vz<B
httpConnection.setRequestProperty("User-Agent","NetFox"); Z(xn-
V :d/;~
rp(`V@x3
int responseCode=httpConnection.getResponseCode(); &,NHk9.aq
if(responseCode>=400) *2;w;(-s
{ Y`lC4*g
processErrorCode(responseCode); MzJ5_}
return -2; //-2 represent access is error <;v{`@\j{
} x6:$lZ(
~POe0!}
#H7(dT
String sHeader; 4I{|M,+
Eq'{uV:
QD\S E
for(int i=1;;i++) 6@Eip[e
{ .z+QyNc:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Dk]Y\:
//Utility.log(in.readLine()); -#)xeW.d
sHeader=httpConnection.getHeaderFieldKey(i); $2;YJjz(
if(sHeader!=null) n-H0cm
{ _|*3uGo:
if(sHeader.equals("Content-Length")) J fsCkS
{ ;]<$p[m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mRQ F5W6
break; d*q_DV
} li/O&@g`
} D}b+#G(m[
else eN}FBX#'
break; kQX,MP(
} G=~T)e
} T(ponLh
catch(IOException e){e.printStackTrace ();} `33h4G
catch(Exception e){e.printStackTrace ();} ?P"ht
m;Sw`nw?
3=;iC6 `
Utility.log(nFileLength); W-Hw%bwN/q
ijyj}gpWha
F\Tlpp9
return nFileLength; ly,d =
} F_V~UX1D
/xf%Rp4}
AQ+w%>G6
//保存下载信息（文件指针位置） (VBoZP=W
private void write_nPos() Q v{q:=k
{ siyJjE)}w
try{ '<1T>|`/t
output = new DataOutputStream(new FileOutputStream(tmpFile)); >@ge[MuS
output.writeInt(nStartPos.length); 1j0yON
for(int i=0;i<nStartPos.length;i++) =>S5}6
{ +TUtVG
// output.writeLong(nPos); [@>Kd`!'
output.writeLong(fileSplitterFetch.nStartPos); RQ/X{<lQ)
output.writeLong(fileSplitterFetch.nEndPos); !f7}5/YC7v
} 7/aJ?:gX
output.close(); =;@5Ue J
} Y\9uR!0
catch(IOException e){e.printStackTrace ();} aEX+M57k~
catch(Exception e){e.printStackTrace ();} ?CmW{9O
} -Frx{3
G]q6Ika
B.&q]CAv-
//读取保存的下载信息（文件指针位置） z,DEBRT+
private void read_nPos() 0>E`9|
{ WOgbz&S?J
try{ v\\Z[,dK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]9A9q<lZ
int nCount = input.readInt(); 8 wC3}U
nStartPos = new long[nCount]; pN%L3?2
nEndPos = new long[nCount]; >rYP}k
for(int i=0;i<nStartPos.length;i++) ,gkxZ{Eh
{ h-jea1m
nStartPos = input.readLong(); <R]?8L0{h
nEndPos = input.readLong(); B8B^@
} ^>k[T.
input.close(); gX6'!}G8]
} m_(+-G
catch(IOException e){e.printStackTrace ();} _W?}%;
catch(Exception e){e.printStackTrace ();} oN)K2&M0
} ,|T
^pZ(^
C/ ;f)k<
private void processErrorCode(int nErrorCode) Y Xn)?
{ VCvuZU{<
System.err.println("Error Code : " + nErrorCode); Y.Gr(]tk
} tr/S*0$
&?YQVwsN
-Ux/ Ug@
//停止文件下载 ,{:5Z:<|
public void siteStop() Fwho.R-.
{ =b !f
bStop = true; 5:56l>0
for(int i=0;i<nStartPos.length;i++) MdEZ839J
fileSplitterFetch.splitterStop(); Xg.\B1d
Ibpk\a?A{
G9}[g)R*
} Mx$VAV^\
} 9\Yj`,i5
//负责部分文件的抓取 :5h&f
**FileSplitterFetch.java l'-iIbKX
*/ |!rD2T\Ef
package NetFox; dos$d3B4
j:]/AReOL
yrkd#m
import java.io.*; yfuvU2nVH
import java.net.*; y;#p=,r
E: XzX Fxx
#7gOtP#{
public class FileSplitterFetch extends Thread { 7nIg3s%
h}+,]^
J/RUKhs/
String sURL; //File URL QGLfZvTT
long nStartPos; //File Snippet Start Position QD /| zi
long nEndPos; //File Snippet End Position Y@#~8\_
int nThreadID; //Thread's ID eMWY[f3
boolean bDownOver = false; //Downing is over n;O 3.2
boolean bStop = false; //Stop identical DB%=/ \U
FileAccessI fileAccessI = null; //File Access interface m}F1sRkdQ
@c7 On)sy
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S/7D}hJ
{ CBi V':;
this.sURL = sURL; Ig5J_Z^]b
this.nStartPos = nStart; }5DyNfZ]+0
this.nEndPos = nEnd; (Rs<'1+>
nThreadID = id; V^?+|8_(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 183'1Z$KA
} @@!t$dD
)"j_NlO
Z@~8iAgE
public void run() W&Fa8
{ PjRKYa_U
while(nStartPos < nEndPos && !bStop) 3tOnALv
{ SznNvd <
B;?a. 81~
$,'r} %
try{ 7xWX:2l*?
URL url = new URL(sURL); CIYD'zR[2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =B;rj
httpConnection.setRequestProperty("User-Agent","NetFox"); ?uh7m2l0D
String sProperty = "bytes="+nStartPos+"-"; -,zNFC:6g
httpConnection.setRequestProperty("RANGE",sProperty); q]'VVlP)
Utility.log(sProperty); :Wb+&|dU
EY> %#0
kiqq_`66
InputStream input = httpConnection.getInputStream(); @8V8gV?zm
//logResponseHead(httpConnection); Z>Sv[Ec
(lt/ t
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byte[] b = new byte[1024]; iCz,|;w%
int nRead; =o+t_.)N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Lqwc:%Y:_
{ +a;:7[%&
nStartPos += fileAccessI.write(b,0,nRead); Qv']*C[!z
//if(nThreadID == 1) /R F#B#9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -+O8v;aC'
} k('2K2P
&b{L|I'KYT
.,tf[w 71
Utility.log("Thread " + nThreadID + " is over!"); +F+jC9j(<
bDownOver = true; ]sbu9O ^"f
//nPos = fileAccessI.write (b,0,nRead); MF%9
} :)mV-(+o
catch(Exception e){e.printStackTrace ();} \kC/)d
} ]FsPlxk6
} VI37
$Fr$9 jq&
cAIS?]1
//打印回应的头信息 W 4 )^8/
public void logResponseHead(HttpURLConnection con) O:k@'&
{ Fvi<5v
for(int i=1;;i++) :c<C;.
{ mezP"N=L~
String header=con.getHeaderFieldKey(i); qj=12;
if(header!=null) C2DNyMu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UIhB
Utility.log(header+" : "+con.getHeaderField(header)); cBc6*%ZD
else !k%Vw18
break; hM+nA::w
} JnPA;1@/
} bzB9u&
[R& P.E7w'
rS6iZp,
public void splitterStop() MhJq~G p
{ ]$KH78MTW
bStop = true; /5zzzaj{
} kw?RUt0-V
X~n Kuo
[ub,&j^
} 5E}0<&
.B>|>W O
l3(k
/* /AW6XyMD_
**FileAccess.java hb^e2@i;Oq
*//文件访问(定位，写) @HaWd3
package NetFox; 2u#{K9g
import java.io.*; +O9l@X$l=
/m9t2,KB
Q_M2!qj
public class FileAccessI implements Serializable{ D~8f6Ko"m
?Tb'J`MO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 eN,m8A`/S
RandomAccessFile oSavedFile; (Tc ~
long nPos; hLJO\=0rJz
yh lZdF
scN}eg:5
public FileAccessI() throws IOException 2lXsD;[
{ "52wa<MVJ
this("",0); J& yDX>
} !tX14O~B-
0H;dA1
lzl4pnj
public FileAccessI(String sName,long nPos) throws IOException ITq+Hk R
{ i~k?k.t8
oSavedFile = new RandomAccessFile(sName,"rw"); qdUlT*fw
this.nPos = nPos; F'|,(P
oSavedFile.seek(nPos); ^3AJYu
} -/7[_,
Tcr&{S&o
/`2VJw
public synchronized int write(byte[] b,int nStart,int nLen) %xWmzdn
{ Q;5aM%a`
int n = -1; P),%S9jP;
try{ NL2n\%n
oSavedFile.write(b,nStart,nLen); Zw"6-h4
n = nLen; M,y='*\M
} ]FQ4v.7
catch(IOException e) E2%7v
{ H$\?D+xlf
e.printStackTrace (); hoSk
} s7T=/SC54
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<%) :'0q&
return n; u%v^(9z
} s7df<dBC
h'T\gF E%
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} WDgp(Av!
nE::9Yh8z
(}]74Lc
/* "ZT=[&2
**SiteInfoBean.java v-OGY[|97
*/ Ya\G/R
package NetFox; _%<7!|"
b*.)m
#v~zf@<KLB
public class SiteInfoBean { ux{OgFfi
?55('+{l
AGrGZ7p]
private String sSiteURL; //Site's URL F fl`;M
private String sFilePath; //Saved File's Path =>-b?F0(c
private String sFileName; //Saved File's Name "fz-h
private int nSplitter; //Count of Splited Downloading File TX;OA"3=\-
%'^m6^g;
.8.ivfmJh
public SiteInfoBean() )@))3
{//nSplitter的缺省值为5 EKwS~G.b!
//default value of nSplitter is 5 X(Ef=:
this("","","",5); )Q7;)iPY#
} Hk3HzN3
9chiu%20
Q"Q|]f*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q@Q|oB0W$)
{ $Q]`+:g*}
sSiteURL= sURL; 7e}p:Vfp
sFilePath = sPath; TpMfk7-
sFileName = sName; ?e&CbVc4
this.nSplitter = nSpiltter; S2j7(T;~YB
iAup',AZg
[iL2c=_
} jY ^ndr0;
]1D>3
B[b'OtH
public String getSSiteURL() i?*&1i@
{ h1)p{5}H
return sSiteURL; 1F[; )@
} {n.g7S~
HjnHl-
/[{?zS{
public void setSSiteURL(String value) Td8'z'
{ t(}&<<1Bz
sSiteURL = value; wiwJD}3h'
} nC>#@*+jK
;O5NZa!.73
Wy4v~]xd%
public String getSFilePath() ~zYp(#0op
{ 'HOcK8}b
return sFilePath; E*RP8
} hkW"D<ii-
hM>xe8yE
vuw1ycy)
public void setSFilePath(String value) ?\^u},HnE|
{ )xTp7YnZ;
sFilePath = value; bh+R9~
} ed\,FWR
'7_'s1
Y]P $|JW):
public String getSFileName() y>wr $
{ D8Ni=.ALL
return sFileName; s,` n=#
} +{Q\B}3cj1
i<%(Z[9Lk
.dM 0
public void setSFileName(String value) /a9+R)Al
{ zRf]SZ(tO
sFileName = value; {9C(\i +
} v SWqOv$
{/B) YR
s'LG3YV-<
public int getNSplitter() ;5 IS58L
{ 6 t A?<S
return nSplitter; Yz%=
} 4I,@aj46
:()4eK/\
_VY]
public void setNSplitter(int nCount) q$EVd9aN
{ 'n>|jw)
nSplitter = nCount; hpAIIgn
} %iJ6;V4
} UbMcXH8=F
Bv9;q3]z-
]~a!O
/* xn6E f"
**Utility.java tP3H7Yl!g
*/ 4&`66\p;
package NetFox; CQv [Od
dB_\,%vAd
b_wb!_
public class Utility { tQ|b?3
]JhtO{
a"WnBdFZ
public Utility() ~vF.k,
{ n,AN&BZ
^//N-?Fx
u2Rmp4]
} (:[><-h.
zIdQ^vm8Q
//线程睡眠 *>\RGL;]8
public static void sleep(int nSecond) Z;%qpsq
{ kMI\GQW
try{ Ex@#!fz{%
Thread.sleep(nSecond); w#JF7;
} ]8H;LgM2
catch(Exception e) Oe;9[=L[
{ 7:1Hgj(
e.printStackTrace (); ?m~x%[Vn
} zGz5|u
} SM^6+L"BE
y()#FRp7
//日志 .Hgiru&
public static void log(String sMsg) kxf'_Nzy
{ OSSMIPr
System.err.println(sMsg); +}^} <|W6
} _IgG8)k;
"%}PVO!
I7[+:?2
public static void log(int sMsg) e?f[t*td
{ *b7v)d#
System.err.println(sMsg); e7hPIG
} <BO|.(ys
} ;dB=/U>3U
~xHr/:
w$&10
/* y XS/3_A{
**TestMethod.java 69IBG,N'
*/ s';jk(i3
package NetFox; ^ro?.,c T
S++}kR);
ZZeqOu7^
public class TestMethod { u\Xi]pZ@X]
"M?(Ax
NtA}I)'SWU
public TestMethod() lhxhAe
{ ///xx/weblogic60b2_win.exe n P69W
try{ wefQmRK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1p{\jCi,2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z:fd'NC
SiteFileFetch fileFetch = new SiteFileFetch(bean); <:%Iq13D
fileFetch.start(); aV>w($tdd
} \kg2pF[V
catch(Exception e){e.printStackTrace ();} QDgOprha
>\@6i s
gbI0?G6XN/
} C6/,-?%)
=-vk}O0C
"3\)@
public static void main(String[] args) 'x!q*|zF2
{ y2<g96
new TestMethod(); KIuYWr7&
} rW1>t+
} \!631FcQ
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