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)); seeBS/%
} 18:%~>.!
for(int i=0;i<nEndPos.length-1;i++) KJZ4AWH`
{ K\c#ig
nEndPos = nStartPos[i+1]; 3"\lu?-E
} FJ?IUy 6
nEndPos[nEndPos.length-1] = nFileLength; E8&TO~"a]e
} @7n"yp*"
} X!g#T9kG
|$_sX9\`?|
D.XvG_
//启动子线程 QP J4~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; VVOd]2{
for(int i=0;i<nStartPos.length;i++) FaJ&GOM,
{ jrh43 \$*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3=ymm^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v|2T%y_ u
nStartPos,nEndPos,i); q> C'BIr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $iz|\m
fileSplitterFetch.start(); GR32S=\
} [!OxZ!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6)Lk-D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8}UIbF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H7:] ]j1
nEndPos = " + nFileLength); I~XSn>-H
// fileSplitterFetch[nPos.length-1].start(); ?6Y?a2 |
y'*K|aTG
P";'jVcR
//等待子线程结束 +K4}Dmg
//int count = 0; n.0fVV-A
//是否结束while循环 J/*`7Pd
boolean breakWhile = false; IO-Ow!
6NHX2Ja
wAW5 Z0D
while(!bStop) @MCg%Afw
{ D d</`iUq
write_nPos(); ixD)VcD-f
Utility.sleep(500); HA>OkA/
breakWhile = true; oILZgNe'
y h9*z3
p.?rey<%
for(int i=0;i<nStartPos.length;i++) ,\%c^,HLJ
{ !Q0w\j h
if(!fileSplitterFetch.bDownOver) A~t j/yq9
{ B_m8{44zM
breakWhile = false; 9mTJ|sN:e
break; Y`SvMkP)+
} :G%61x&=Zc
} SNI)9k(T{
if(breakWhile) q5)O%l!
break; G*P#]eO
K(,F~.<
fS78>*K
//count++; ._{H~R|
//if(count>4) A{D];pE`
// siteStop(); JrRH\+4K
} F@B]et7
b!5~7Ub.No
b2&0Hx
System.err.println("文件下载结束！"); *YuF0Yt
} I(BQ34q
catch(Exception e){e.printStackTrace ();} 5taT5?n2
} l)l^[2
QX'qyojxN
m`^q <sj
//获得文件长度 tG22#F`
public long getFileSize() E92KP?i
{ [j/9neaye
int nFileLength = -1; UhQj Qaa~
try{ ,M ^<CJ
URL url = new URL(siteInfoBean.getSSiteURL()); p]2128kqx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K:#I
httpConnection.setRequestProperty("User-Agent","NetFox"); &powy7rR
)W _v:?A9
^Q?
int responseCode=httpConnection.getResponseCode(); nazZ*lC
if(responseCode>=400) DAr1C+Dy
{ kzUIZ/+ZL,
processErrorCode(responseCode); mLLDE;7|}
return -2; //-2 represent access is error y(yHt=r
} eiaFaYe\
rlSeu5X6
L2i_X@/
String sHeader; uGK.\PB$
!@*7e:l
E,x+JeKV
for(int i=1;;i++) (m(JK^
{ u.m[u)HQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +.b,AqJ/
//Utility.log(in.readLine()); aP@N)"
sHeader=httpConnection.getHeaderFieldKey(i); 9Uekvs=r=M
if(sHeader!=null) 9ZsVy
{ Nkth>7*
if(sHeader.equals("Content-Length")) 3J|F?M"N7
{ U@)eTHv}6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z3m85F%dR
break; SBk4_J/_
} }I6veagK
} `V)8 QRN(
else BLf>_bUk
break; S3*`jF>q
} s.QwSbw-g
} +RMSA^
catch(IOException e){e.printStackTrace ();} jTtu0Q|
catch(Exception e){e.printStackTrace ();} }"P|`"WW
&P}_bx
)|R)Q6UJ
Utility.log(nFileLength); IT7wT+
RVA(Q[ ;
;yLu R
return nFileLength; 8hz^%vm
} 2M#Q.F
f<fXsSv(
%G/hD
//保存下载信息（文件指针位置） }mYx_=+VX
private void write_nPos() RYQR(v
{ uLL]A>vR
try{ j<99FW"@e
output = new DataOutputStream(new FileOutputStream(tmpFile)); .B]MpmpK
output.writeInt(nStartPos.length); vkx7paY_
for(int i=0;i<nStartPos.length;i++) #@9/g
{ F^t DL:
// output.writeLong(nPos); 2W96Zju\
output.writeLong(fileSplitterFetch.nStartPos); Is)u }
output.writeLong(fileSplitterFetch.nEndPos); R'bTN|Cq
} wOEj)fp.
output.close(); ,j2Udn}
} 7uS~MW
catch(IOException e){e.printStackTrace ();} RXpw!
catch(Exception e){e.printStackTrace ();} ,]ma+(|
} vv3* j&I
J6s`'gFns
QT< }] 0
//读取保存的下载信息（文件指针位置） Yq0| J
private void read_nPos() hk(ZM#Bh
{ x=hiQ>BIO0
try{ 8>2.UrC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0[NZ>7wqMZ
int nCount = input.readInt(); 1MP~dRZ$
nStartPos = new long[nCount]; ?cBwPetp
nEndPos = new long[nCount]; [fya)}
for(int i=0;i<nStartPos.length;i++) '8RsN-w
{ #zv3b[@
nStartPos = input.readLong(); BOb">6C
nEndPos = input.readLong(); dh`K`b4I
} d6?j`~[7#-
input.close(); }{K) 4M
} |C;=-|
catch(IOException e){e.printStackTrace ();} :t"^6xt
catch(Exception e){e.printStackTrace ();} (^8Y|:Tz
} n71r_S*
Gv!2f
=1FRFZI!j
private void processErrorCode(int nErrorCode) ?/wm(uL
{ nMq,F#`3N
System.err.println("Error Code : " + nErrorCode); 'Vzp2
} r_)' Ps
{nBhdM:i
9|^2",V
//停止文件下载 X:f UI4
public void siteStop() p,5i)nEFj
{ .LPV#&
bStop = true; VZp5)-!\
for(int i=0;i<nStartPos.length;i++) -/wtI
fileSplitterFetch.splitterStop(); /kZebNf6H
YFLZ%(
gD-d29pQ
} 2.`\
} 7X`g,b!
//负责部分文件的抓取 |PvPAPy)uu
**FileSplitterFetch.java YquI$PV _
*/ *<$*"p
package NetFox; gDQ^)1k
& TCkpS
f&NgS+<K$
import java.io.*; @+&LYy72
import java.net.*; 9a[9i}_
5N#aXG^9
JinUV6cr
public class FileSplitterFetch extends Thread { a kkNI3
>2Y=*K,:
!4ocZmj\
String sURL; //File URL 6iry6wcHm
long nStartPos; //File Snippet Start Position z 4e7PW|
long nEndPos; //File Snippet End Position u4*BX&
int nThreadID; //Thread's ID H9Gh>u]}
boolean bDownOver = false; //Downing is over 0gu_yg!R
boolean bStop = false; //Stop identical +WZX.D
FileAccessI fileAccessI = null; //File Access interface T )&A2q
8v6(qBK
}g@v`5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \:P>le'1
{ zF@/K`
this.sURL = sURL; 7RQR)DG
this.nStartPos = nStart; mn'A9er
this.nEndPos = nEnd; SjK
nThreadID = id; FBG4pb9=~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OMky$d#
} i:dR\|B
\Zb;'eDv
'"52uZ{
public void run() NYhB'C2
{ H[T?\Lq
while(nStartPos < nEndPos && !bStop) +l42Awl>K
{ 6u?>M9
,S\CC{!
\a<wKTkn
try{ {aZ0;
URL url = new URL(sURL); [=C6U_vU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D=TvYe
httpConnection.setRequestProperty("User-Agent","NetFox"); t <~h'U
String sProperty = "bytes="+nStartPos+"-"; pG_;$8Hc
httpConnection.setRequestProperty("RANGE",sProperty); Xa[.3=bV?
Utility.log(sProperty); 3s*mbk[J
L]7=?vN=8
)w em|:H
InputStream input = httpConnection.getInputStream(); pR<`H'
//logResponseHead(httpConnection); cUk7i`M;6
c&6I[R
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byte[] b = new byte[1024]; hy1oq7F(Q
int nRead; Fk7?xc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZT*ydln
{ _=>He=v/
nStartPos += fileAccessI.write(b,0,nRead); 50h! X9
//if(nThreadID == 1) 5{TsiZh4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +SzU
} |*Yr<zt
BX/8O<s0
{'flJ5]
Utility.log("Thread " + nThreadID + " is over!"); wKh4|Ka
bDownOver = true; |o"?gB}Dh
//nPos = fileAccessI.write (b,0,nRead); E#34Wh2z
} 4IK(7
catch(Exception e){e.printStackTrace ();} Gf6p'(\zun
} \0gis#
} =}^9 wP
,i NXK
Z9E\,Ly
//打印回应的头信息 !vi>U|rh
public void logResponseHead(HttpURLConnection con) J`Q>3]wL
{ 1dY}\Sp
for(int i=1;;i++) [|wZ77\
{ p>,|50|
String header=con.getHeaderFieldKey(i); YRk(u7:0
if(header!=null) &<g|gsG`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /V8#[9K
Utility.log(header+" : "+con.getHeaderField(header)); nbp=PzZy
else t^-d/yKt0w
break; Eh`7X=Z7E
} ?PxP% $hS
} _RYxD"my
UXz<)RvB
sjTZF-
public void splitterStop() >{]%F*p4
{ 234p9A@
bStop = true; N];NAMp
} ldcqe$7,
qbr$>xH
GAzU?a{S
} w(Ovr`o?9t
EP&,MYI%E
5pG}Yk_(x
/* Y Uc+0
**FileAccess.java f`(UQJ
*//文件访问(定位，写) R{4^t97wH{
package NetFox; 9=M$AB
import java.io.*; ZoqZap6e
(Rh,,
P5V}#;v
public class FileAccessI implements Serializable{ "{+QW
c]<5zyl"j1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Es`Px_k
RandomAccessFile oSavedFile; 2qNt,;DQ
long nPos; qo~O|~
octL"t8w
s^TZXCyF o
public FileAccessI() throws IOException X`/k)N>l
{ ]q[D>6_
this("",0); 1\m[$Gs:
} -ad{tJV|
B@))8.h]
e"cXun4nS=
public FileAccessI(String sName,long nPos) throws IOException uMv,zO5
{ c#]4awHU
oSavedFile = new RandomAccessFile(sName,"rw"); 3&4(ZH=
this.nPos = nPos; z6P$pqyF
oSavedFile.seek(nPos); zI uJ-8T"
} kH1~k,|\&K
8W7J3{d
VGN5<?PrN
public synchronized int write(byte[] b,int nStart,int nLen) Oo~; L,
{ }v{LRRi
int n = -1; (mB&m@-N
try{ Rv>-4@fMJ
oSavedFile.write(b,nStart,nLen); 2tO,dx
n = nLen; R\f+SvE
} lVa%$F{Pq
catch(IOException e) `}\ "Aw c
{ G_JA-@i%
e.printStackTrace (); q i;1L Kc
} t?gic9 q
^76]0`gS
\@zHON(
return n; wlvgg
} H?Wya.7
I{2hfKUe`
i]4I [!
} }<r)~{UV
vr l-$ii
Q&;9x?e
/* o|:b;\)b
**SiteInfoBean.java *^4"5X@
*/ :Yl-w-oe
package NetFox; _VN?#J)o
`wVyb>T
WH}y"W
public class SiteInfoBean { ITBE|b
G` A4|+W"
BU_nh+dF
private String sSiteURL; //Site's URL reWot&;
private String sFilePath; //Saved File's Path GxxW&y
private String sFileName; //Saved File's Name m(!FHPvN
private int nSplitter; //Count of Splited Downloading File "+s++@ z
aFYIM`?(
6{b>p+U
public SiteInfoBean() >bW#Zs,6
{//nSplitter的缺省值为5 T5h H
//default value of nSplitter is 5 Y3b *a".X
this("","","",5); K%oG,-wdg
} ,O(hMI85]
ZE}}W_
~>|ziHx
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4B.*g-L
{ /8S>;5hvK@
sSiteURL= sURL; L0o\J` :
sFilePath = sPath; !|(NgzDP/
sFileName = sName; rILYI;'o
this.nSplitter = nSpiltter; fHFE){
=^?/+p8k
WsB?C&>x
} g7H(PF?
hVY$;s
n[rCQdM&U"
public String getSSiteURL() Dd|VMW=
{ z{QqY.Gu{G
return sSiteURL; =s6 opL)
} Bzf^ivT3L
6gDN`e,@
hZb_P\1X
public void setSSiteURL(String value) L/K(dkx
{ "tK=+f`NM
sSiteURL = value; nw<uyaU-t
} :A;RH
P%n>Tg80M
(ZlU^Gw#UB
public String getSFilePath() 307I$*%W
{ HPVEnVn
return sFilePath; 5^Zg>I
} .}+}8[p4l
*un^u-;
UiNP3TJ'L
public void setSFilePath(String value) bN.Pex
{ &p,]w~d,U
sFilePath = value; %C]>9."
} |w=zOC;v
3so%gvY.'
%yC,^
public String getSFileName() xIn:ZKJ'
{ I/N *gy?*
return sFileName; LP=)~K<
} /9X7A;O
[Rb+q=z#
<UCl@5g&
public void setSFileName(String value) nk:)j:fr
{ mE[y SrV
sFileName = value; :T~[
} cwL_tq
>Q*Wi
[]T8k9g/-
public int getNSplitter() wIgS3K
{ lhJ'bYI
return nSplitter; 73-p*o(pt
} $cgcX
,x$,l
6\t@)=C,Q
public void setNSplitter(int nCount) +C)~bb*
{ qP ,EBE
nSplitter = nCount; ~#/
} 05R@7[GWq
} EM_d8o)`B
TA\vZGJ('
k7^5Bp8=
/* TqQ[_RKg2
**Utility.java ?]5qr?W%
*/ 4ppz,L,4
package NetFox; {RPI]DcO/
SX#&5Ka/
C#pjmT_
public class Utility { gDzK{6Z}
,: ^u-b|
A}w/OA97RO
public Utility() fV~~J2IK
{ $Kd>:f=A
L50n8s
BLFdHB.$T
} tX[WH\(xI
bMBLXk
//线程睡眠 MfkZ
public static void sleep(int nSecond) d=^z`nt !R
{ 62u4-}JzF
try{ 1mJHued=6
Thread.sleep(nSecond); h`KU\X )A
} }a/Cro.~4
catch(Exception e) 0"#HJA44
{ hGrdtsH?
e.printStackTrace (); 0\$2X- c
} lxi<F
} tp|d*7^i
W3RT{\
//日志 JS77M-Ac
public static void log(String sMsg) `h;[TtIX4
{ 5-M-X#(
System.err.println(sMsg); X?Au/
} /RF7j;
nFn5v'g
N21smC}
public static void log(int sMsg) )e{}V\;q
{ adw2x pj
System.err.println(sMsg); Zc2PepIg
} ?Ob3tUz2
} v0y(58Rz.
&{i{XcqH'
28nFRr
/* Js;h%
**TestMethod.java g .\[o@H
*/ W>LR\]Ti@
package NetFox; E'8;10s
= /8cp
cnLro
public class TestMethod { uw7zWJ n
{b{s<@?
~5g~;f[4
public TestMethod() YK\X+"lB
{ ///xx/weblogic60b2_win.exe 0`hdMLONR
try{ xkn;,`t^lJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ME dWLFf
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [gB+C84%%
SiteFileFetch fileFetch = new SiteFileFetch(bean); u&NV,6Fj2[
fileFetch.start(); b]y2+A.n
} )*[3Vq
catch(Exception e){e.printStackTrace ();} &FD>&WRV
:-'qC8C
kP"9&R`E
} HV.t6@\};
Vc2`b3"Br
L$-T,Kze
public static void main(String[] args) }*-@!wc-N
{ Uv.)?YeGh
new TestMethod(); 3Y &d=
} '%D7C=;^
} r,udO,Yi=c
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