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)); Q@6OIE
} G4{ zt3{
for(int i=0;i<nEndPos.length-1;i++) PCF!Y(l
{ B4bC6$Lg
nEndPos = nStartPos[i+1]; *>h"}e41
} U=\ZeYK.
nEndPos[nEndPos.length-1] = nFileLength; wqx@/--E(
} "X4OUk
} c}kZx1
A1Ia9@=Mf
S75wtz)e
//启动子线程 hn{]Q@(I
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >0~|iRySi
for(int i=0;i<nStartPos.length;i++) r&@#,g
{ 75v 5/5zRn
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Bwj^9J/ob
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), } 1^/[?
nStartPos,nEndPos,i); 6T! *YrS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2Vas`/~u~
fileSplitterFetch.start(); `*mctjSN
} jq yqOhb4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *kY\,r&!P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); AP'UcA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v]& )+0
nEndPos = " + nFileLength); XrS.[
// fileSplitterFetch[nPos.length-1].start(); -^]8wQU
xQ\/6|
kE;h[No&K
//等待子线程结束 89*CoQ
//int count = 0; 3%{A"^S=}
//是否结束while循环 I:CnOpR>A
boolean breakWhile = false; mYJ%gdTpo
srXGe`VL
.Qm"iOyM
while(!bStop) 5+\[x`
{ qqA(Swe)T
write_nPos(); }&BE*U8_
Utility.sleep(500); rCR?]1*Z
breakWhile = true; (Gr8JpV
O]>9\!0{
q4'szDYO2
for(int i=0;i<nStartPos.length;i++) fw$/@31AP?
{ ;wwhW|A
if(!fileSplitterFetch.bDownOver) 8!2NZOZOS
{ 9\ZlRYnc=
breakWhile = false; Yf:xM>.%
break; };6[Byf
} nAPSs]D
} {G&*\5W
if(breakWhile) $"1Unu&P
break; Aw9se"d
z )s{>^D
W+36"?*k3
//count++; Q]]}8l2
//if(count>4) <@6K(
// siteStop(); 3>YG
} SxMmy
Vp{! Ft8>
A:PQIcR;V
System.err.println("文件下载结束！"); Wd#r-&!6j
} /tR@J8pV
catch(Exception e){e.printStackTrace ();} "| cNY_$&s
} d 4w+5H"u
CB_ww=
ts%XjCN[
//获得文件长度 7s@%LS
public long getFileSize() WP[h@#7<
{ 4>eY/~odq]
int nFileLength = -1; !)gTS5Rh:
try{ 6$$4!R-
URL url = new URL(siteInfoBean.getSSiteURL()); c<-F_+[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 11t+ a,fM
httpConnection.setRequestProperty("User-Agent","NetFox"); .RFijr
Gx/sJ(
_^K)>
int responseCode=httpConnection.getResponseCode(); IaMZPl
if(responseCode>=400) XgL-t~_
{ jkCa2!WQ'i
processErrorCode(responseCode); C^9G \s'
return -2; //-2 represent access is error c-3-,pyM_T
} Br^4N9
HwfBbWHr'
"#,]`ME;
String sHeader; YHBH9E/B
~2u~}v5m7
1AMxZ (e
for(int i=1;;i++) 9RA~#S|(T
{ ~,[-pZ<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KG9h rT
//Utility.log(in.readLine()); r+%:rFeX
sHeader=httpConnection.getHeaderFieldKey(i); 2..b/
if(sHeader!=null) /$ Gp<.z
{ zURxXo/\V
if(sHeader.equals("Content-Length")) cV^r_E\m
{ 6[ }~m\cY
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r9nH6 Md\
break; v"wxHro
} !qGER.
} 4@ EY+p
else eaLR-+vEB
break; RhwqAok|lj
} p1~u5BE7O
} U9^o"vT
catch(IOException e){e.printStackTrace ();} z}?*1c
catch(Exception e){e.printStackTrace ();} L&h@`NPO a
PNy)TqdRS
,@I_b
Utility.log(nFileLength); B-'oB>|
(=#[om(A
u\-WArntc
return nFileLength; $Ro]]NUz|
} Mn$w_Z?
K+2k}Hx6J
1,UeVw/
//保存下载信息（文件指针位置） v C,53g
private void write_nPos() p5F=?*[}
{ iA*^`NMaT
try{ ^na8d's:
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]?KTw8j}
output.writeInt(nStartPos.length); lO^Ly27
for(int i=0;i<nStartPos.length;i++) y[QQopy4:
{ NQBa+N
// output.writeLong(nPos); W)F<<B,
output.writeLong(fileSplitterFetch.nStartPos); JF{yhx,+p
output.writeLong(fileSplitterFetch.nEndPos); U~9Y9qzy,
} P`z#tDT^"
output.close(); v9?hcJ=
} R"@J*\;$T
catch(IOException e){e.printStackTrace ();} H}v.0R
catch(Exception e){e.printStackTrace ();} '+?L/|'
} 6<aZr\Ufg
4#<r}j12z
hd+(M[C<9
//读取保存的下载信息（文件指针位置） `N;}Gf-'
private void read_nPos() ( X(61[Lu
{ 5:S=gARz
try{ tc-pVw:TV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t<8vgdD
int nCount = input.readInt(); Oz8"s4Y7
nStartPos = new long[nCount]; Z8vMVo
nEndPos = new long[nCount]; Ug :3)q[O
for(int i=0;i<nStartPos.length;i++) _FpZc?=
{ 8+}yf.`
nStartPos = input.readLong(); RbOEXH*]
nEndPos = input.readLong(); cV;<!f+
} VTS7K2lBvX
input.close(); 2pr#qh8
} j:|um&`)
catch(IOException e){e.printStackTrace ();} d,%e?8x5
catch(Exception e){e.printStackTrace ();} #eRrVjbo
} (RXOv"''=
~7CQw^"R@
V$ 8go#5
private void processErrorCode(int nErrorCode) P:lmQHls+
{ &Tc:WD
System.err.println("Error Code : " + nErrorCode); qg7qTF&
} 'YQVf]4P
{@1;kG
sR~D3-
//停止文件下载 pFB^l|\ ]
public void siteStop() cy_'QS$W
{ j 3/ I=
bStop = true; hk5[ N=
for(int i=0;i<nStartPos.length;i++) pJg'$iR!/
fileSplitterFetch.splitterStop(); =1|^) 4M,x
V(gmC%6%l*
qu8!fFQjYL
} R_DstpsT
} 0iKSUwps
//负责部分文件的抓取 2wCSjAWWh(
**FileSplitterFetch.java JD\yl[ac%
*/ o*]Tqx
package NetFox; y nue;*rM
3VI[*b
u"$=:GK
import java.io.*; 7LFJi@*8
import java.net.*; F.rNh`44
Xu.Wdl/{Ra
7lLh4__;`6
public class FileSplitterFetch extends Thread { A{Kc"s4fO
<w,NMu"
dnwTD\),
String sURL; //File URL RZY[DoF8u
long nStartPos; //File Snippet Start Position @Sr{6g*I
long nEndPos; //File Snippet End Position {th=MldJ?
int nThreadID; //Thread's ID sn!E$ls3O
boolean bDownOver = false; //Downing is over Q1 t-Z;X
boolean bStop = false; //Stop identical @p$Nw.{'
FileAccessI fileAccessI = null; //File Access interface DPWt=IFU
l1M %
AfAlDM'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g)3HVAT
{ Vx Vpl@
this.sURL = sURL; (^{tu89ab
this.nStartPos = nStart; '3i,^g0?t0
this.nEndPos = nEnd; =00c1v
nThreadID = id; ^y,Ex;6o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c 5%uiv]
} X[SdDYMY
>P<8E2}*
04j]W]8#
public void run() =8o$
{ 5n0B`A
while(nStartPos < nEndPos && !bStop) Sux/='
{ icrcP ~$A
MQ#nP_i
_\2Ae\&c
try{ xS'Kr.S
URL url = new URL(sURL); h&|S*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ShIJ6LZ
httpConnection.setRequestProperty("User-Agent","NetFox"); `MLOf
String sProperty = "bytes="+nStartPos+"-"; ]Pp}=hcD
httpConnection.setRequestProperty("RANGE",sProperty); p{vGc-zP.
Utility.log(sProperty); /!i`K{
w=QlQ\
&E?TR A# E
InputStream input = httpConnection.getInputStream(); Vr^UEu.w?
//logResponseHead(httpConnection); Vsj1!}X:
XsEotW
/&i6vWMhP
byte[] b = new byte[1024]; =#Z+WD-E
int nRead; o*t4zF&n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j&N {j_M
{ im&Nkk4n@
nStartPos += fileAccessI.write(b,0,nRead); : MEB] }
//if(nThreadID == 1) QM) ob
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5(\H:g\z
} mx!EuF$I
8}?wi[T
2JhE`EVH
Utility.log("Thread " + nThreadID + " is over!"); X T<SR]
bDownOver = true; w7%.EA{N
//nPos = fileAccessI.write (b,0,nRead); 1RgERj
} jhJ'fI
catch(Exception e){e.printStackTrace ();} FX %(<M
} !jTxMf
} h}U>K4BJ
Wt M1nnJp
B'v~0Kau
//打印回应的头信息 @kPe/j/[1
public void logResponseHead(HttpURLConnection con) fq[1|Q
{ 1xD?cA\vu
for(int i=1;;i++) K%g_e*"$
{ | 9 <+!t\
String header=con.getHeaderFieldKey(i); 1KadT7<0}
if(header!=null) @$|8zPs
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "(YfvO+
Utility.log(header+" : "+con.getHeaderField(header)); M{jJ>S{g
else 4M)oA|1w
break; $vLGX>H
} 98rO]rg
} RI3GAd
Gspb\HJ^
pt%*Y.)az
public void splitterStop() j0~dJ#
{ )tv~N7
bStop = true; =.]{OT
} |Kq<}R
s}<i[hY>
WjsmLb:5
} 6ltV}Wt-
_oE 7<
=X;h _GQ
/* m2\[L/W]
**FileAccess.java v:gdG|n"
*//文件访问(定位，写) (XNd]G
package NetFox; (5l'?7
import java.io.*; 2@Zw#2|]
pM-mZ/?
jpkKdQX)
public class FileAccessI implements Serializable{ jSQM3+`b
GQ0(lS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =bOMtQ]
RandomAccessFile oSavedFile; 13p.dp`
long nPos; cz1 m05E
P#9Pq,I
=>-W!Of
public FileAccessI() throws IOException 8I7JsCj
{ 2<E@f0BVAy
this("",0); wWVB'MRXB,
} tkP& =$
[ e#[j{
6t{G{ ]
public FileAccessI(String sName,long nPos) throws IOException 4xF}rm
{ cp&1yB
oSavedFile = new RandomAccessFile(sName,"rw"); ge]Z5E(1
this.nPos = nPos; tP89gN^PA|
oSavedFile.seek(nPos); }\QXPU{UVd
} zHD8\*
u`"Y!*[ -
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public synchronized int write(byte[] b,int nStart,int nLen) d~KTUgH'<
{ GA"vJFQ
int n = -1; 0v|qP
try{ $+ORq3
oSavedFile.write(b,nStart,nLen); uMjL>YLq{?
n = nLen; g:YUuZ
} H<"EE15
catch(IOException e) YbF}>1/"
{ z+c'-!e/
e.printStackTrace (); n5Mhp:zc,
} EX@Cf!GjN
|fY#2\)Yx
P6)d#M
return n; oQR?H
} t!59upbN}3
.Ms$)1
Rl'xEtaN
} xLP8*lvy
24*3m&fA*K
t$PJ*F67M
/* (ZP e{;L.
**SiteInfoBean.java 1U(!%},
*/ cR/e Zfl
package NetFox; Gh}* <X;N
hyY^$p+
:BF WX
public class SiteInfoBean { _TyQC1 d
iV:\,<8d
AD>/#Ul
private String sSiteURL; //Site's URL 9hgIQl
private String sFilePath; //Saved File's Path 1[-RIN;U8
private String sFileName; //Saved File's Name f[q_eY
private int nSplitter; //Count of Splited Downloading File gX(8V*os^
x[R?hS,0t
X;v{,P=J
public SiteInfoBean() MfraTUxIo/
{//nSplitter的缺省值为5 212 =+k
//default value of nSplitter is 5 X7SSTcA
this("","","",5); 88}04
} 2<*Yq8
mhF@S@
y2PxC. -
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &zPM#Q
{ u1|v3/Q-
sSiteURL= sURL; qc3?Aplj
sFilePath = sPath; W+.?J 60
sFileName = sName; PPh1y;D
this.nSplitter = nSpiltter; a?)g>e HN
kdMB.~(K=
{"0n^!
} !v*#E{r"g=
[-\DC*6
jRp @-S#V
public String getSSiteURL() sA }X)aP
{ Cyud)BZvm
return sSiteURL; G }M!
} T{ lm z<g
3]>YBbXvE
0.#%KfQ
public void setSSiteURL(String value) 7KtgR=-Lb
{ !9^GkFR6n
sSiteURL = value; +EZr@
} we?t/YB=
QzYaxNGv
JV!}"[
public String getSFilePath() U}{\qs-zt
{ !zxq9IhWR
return sFilePath; +PO& z!F
} tOPkx(
d%Ku'Jy
:$QwOz^N*
public void setSFilePath(String value) CF5%&B
{ N]|U-fN\
sFilePath = value; $-)y59w"
} 7RgnL<t~:8
P2)g%$ME
UL" <V
public String getSFileName() T{T> S%17~
{ 1'5!")r
return sFileName; * =O@D2g0
} gKb5W094@
*oIKddZh
h#8{fr)6
public void setSFileName(String value) s'@@q
{ ]j(Ld\:L
sFileName = value; dRTpGz
} <pUc( tPoz
j MA%`*r
_[ `"E'
public int getNSplitter() 98WJ"f_ #
{ !v3wl0
return nSplitter; 4W+nSv
} yAc}4*;T/
A3zNUad;
/zV0kW>N
public void setNSplitter(int nCount) taOsC!Bp
{ ,I[A~
nSplitter = nCount; 8\Eq(o}7
} 7M9s}b%?
} 3*b!]^d:D
CY9`HQ1
FD}>}fLv
/* g/,O51f'
**Utility.java .]Z,O>N
*/ $E@ke:
package NetFox; o6 [i0S
#/pZ#ny
#60<$HO:Z
public class Utility { 4>@-1nt}
KL*UU,qU
k?=V?JWY
public Utility() Iyvl6
{ SHPZXJ{
\'N|1!EO|t
Bb/aeLv
} jNseD
#kGxX@0
//线程睡眠 8%9OB5?F6
public static void sleep(int nSecond) BcoE&I?[m|
{ 0b}lwo,|\
try{ +<I1@C
Thread.sleep(nSecond); O~&l.>??
} k)USLA
catch(Exception e) r,dxW5v.
{ ^A$~8?f
e.printStackTrace (); ^SRa!8z$W
} 1vxh3KS.
} (.3L'+F
?hpk)Qu
//日志 XC{(O:EG
public static void log(String sMsg) }c,}+{q
{ AuYi$?8|5
System.err.println(sMsg); I!Za2?
} -/&6}lD
VVje|T^{Z
}fs;yPl,
public static void log(int sMsg) )+9D$m=P;
{ Lp*T=]C]
System.err.println(sMsg); G8?<(.pi@
} W.,J'
} efP2C\
am05>c9
`\P:rn95;
/* Y<.F/iaH
**TestMethod.java ArU>./)Q
*/ BmUzsfD
package NetFox; Xc5[d`]
:<IW'
ikRIL2Y
public class TestMethod { |,&!Q$<un
RN:#+S(8
*id|za|:k
public TestMethod() {UZli[W1
{ ///xx/weblogic60b2_win.exe LDvF)Eg
try{ emS+%6U
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T[q-$8U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %dT%r=%Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); |I+E`,n"b
fileFetch.start(); L}a3!33)C
} n8G#TQrAE
catch(Exception e){e.printStackTrace ();} \a]\jZb
,n!xzoX_
c)6Y.[).
} lE|T'?/
Jp-ae0 Ewa
?s"v0cg+
public static void main(String[] args) *E)Y?9u"
{ M9OFK\)
new TestMethod(); =OZ_\vO
} H@j^,
} <7] z'
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