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)); )M.s<Y
} x;)I%c
for(int i=0;i<nEndPos.length-1;i++) e,epKtL
{ u&#>)h
nEndPos = nStartPos[i+1]; ']TWWwj$
} P4q5#r
nEndPos[nEndPos.length-1] = nFileLength; u+Ix''Fn#%
} dkz% Y]
} !DzeJWM|
#<< el;n
L&DjNu`!9
//启动子线程 Sc]K-]1(H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; iq*im$9J
for(int i=0;i<nStartPos.length;i++) F$)l8}
{ 2PYnzAsl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;O% H]oN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \KnRQtlI
nStartPos,nEndPos,i); TdgK.g 4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *0xL(
fileSplitterFetch.start(); Vt(Wy
} q@~g.AMCB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'KA$^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4?1Qe\A^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", '";#v.!
nEndPos = " + nFileLength); ?).;cG:<
// fileSplitterFetch[nPos.length-1].start(); /Ne#{*z)hO
z )'9[t
`=H*4I-"
//等待子线程结束 sko7,&
//int count = 0; ,)Q-o2(C
//是否结束while循环 P !i_?M
boolean breakWhile = false; ;Y\LsmZ;F
"G [Nb:,CR
@w8}]S
while(!bStop) w2.] 3QAZ
{ .qSDe+A
write_nPos(); M!'d
Utility.sleep(500); u:f ]|Q
breakWhile = true; ,fp+nu8,
gLX<>|)*
4HGTgS
for(int i=0;i<nStartPos.length;i++) i8V\x>9
{ IqYJ
if(!fileSplitterFetch.bDownOver) _#sy
{ uP'L6p5
breakWhile = false; uC;_?Bve
break; 3<&:av3
} YSeH;<'
} >`0U2K
if(breakWhile) Zu,:}+niU
break; :awkhx
OF7hp5
^$:w
//count++; QFx3N%
//if(count>4) QT,T5Q%JP:
// siteStop(); d$3rcH1
} h p|v?3(
QEs$9a5TE
rJ Jx8)M
System.err.println("文件下载结束！"); #gQn3.PX+y
} ByY2KJ7
catch(Exception e){e.printStackTrace ();} RqTO3Kf
} 8TFQ%jv
wnokP
Ei_~K';
//获得文件长度 Qb^G1#r@C
public long getFileSize() $Aw@xC^!
{ |T6K?:U7
int nFileLength = -1; [Kwj 7q`
try{ ie6c/5
URL url = new URL(siteInfoBean.getSSiteURL()); %*gf_GeM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &YXJ{<s
httpConnection.setRequestProperty("User-Agent","NetFox"); "tCTkog3]
`MVqd16Y
G x[ZHpy;
int responseCode=httpConnection.getResponseCode(); aj`&ca8
if(responseCode>=400) fs ufYIf
{ 8:{id>Mm^
processErrorCode(responseCode); '(5GRI<
return -2; //-2 represent access is error !"F;wg$
} ELCNf
G]>yk_#/\U
BTkx}KK
String sHeader; XYo,5-
i=EOk}R
EbILAJ
for(int i=1;;i++) E%`J=C}
{ p/<DR|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]lC%HlID
//Utility.log(in.readLine()); '3b\d:hN
sHeader=httpConnection.getHeaderFieldKey(i); r"dIB@
if(sHeader!=null) ]W5*R07
{ 7'IIB1v.\
if(sHeader.equals("Content-Length")) Q~U\f$N
{ ,R[$S"]!SH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); UGPDwgq\v
break; Vu5?;|^:
} :oIBJ u%/
} %)lp]Y33
else 3IMvtg
break; [ \_o_W
} :.x(( FU
} ^o3,YH
catch(IOException e){e.printStackTrace ();} eq6O6-
catch(Exception e){e.printStackTrace ();} DC8#b`j
L0g+RohW
[KK |_
Utility.log(nFileLength); MLWHO$C~T
N1~bp?$1
y&$n[j
return nFileLength; }emUpju<C
} 7_\sx7h{3
Yj&Sb
6|jZv~rS$
//保存下载信息（文件指针位置） aRMlE*yW
private void write_nPos() ~n]5iGz
{ O@Aazc5K
try{ q|D5 A|)
output = new DataOutputStream(new FileOutputStream(tmpFile)); aS [[ AL
output.writeInt(nStartPos.length); L)JB^cxf
for(int i=0;i<nStartPos.length;i++) .t@|2
{ t$!zgUJ
// output.writeLong(nPos); nONuw;K
output.writeLong(fileSplitterFetch.nStartPos); yvB]rz} i
output.writeLong(fileSplitterFetch.nEndPos); ]M5~p^ RB
} >-MnB
output.close(); WN'AQ~qA
} $@z77td3
catch(IOException e){e.printStackTrace ();} U?0|2hR~
catch(Exception e){e.printStackTrace ();} H+[?{+"#@l
} 1 (<n^\J(
eI1zRoIl-
A%8 Q}s$<s
//读取保存的下载信息（文件指针位置） +_]Ui| l
private void read_nPos() (]#^q8)]\9
{ /I7V\
try{ ='m$O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /z-rBfdy^
int nCount = input.readInt(); S8#0Vo$)a
nStartPos = new long[nCount]; 9\_s&p=:.
nEndPos = new long[nCount]; Clum m@z;#
for(int i=0;i<nStartPos.length;i++) P =X]'m_B
{ $Z G&d
nStartPos = input.readLong(); xvTtA61Vp
nEndPos = input.readLong(); Z@Rm^g]o
} .RxTz9(
input.close(); ,t`V^(PEq
} vvxxwZa=O
catch(IOException e){e.printStackTrace ();} Nn05me"X
catch(Exception e){e.printStackTrace ();} W22S/s
} +VUkV-kP
{lds?AuK
2w.FC
private void processErrorCode(int nErrorCode) #kW=|8X
{ +M=h+3hw](
System.err.println("Error Code : " + nErrorCode); {>ba7-Cy+y
} {"wF;*U.V
R{@saa5I(>
UdO8KD#r3
//停止文件下载 SP%X@~d
public void siteStop() :xsZz$
{ `PUqz&
bStop = true; i-CJ{l
for(int i=0;i<nStartPos.length;i++) V(&L
fileSplitterFetch.splitterStop(); *u$aItx
*Dp&;,b
%p}vX9U')
} -gs I:-Xo
} o-8{C0>:
//负责部分文件的抓取 gNZwD6GMe?
**FileSplitterFetch.java v<1@"9EH
*/ >6C\T@{lJ
package NetFox; 5=TgOS]R
r8m}B#W7
a OmG,+o
import java.io.*; J*zzjtY( 1
import java.net.*; M XG>|
o26Y}W
0C<\m\|~k
public class FileSplitterFetch extends Thread { 85E$m'0O
vU>^
0fqcPi
String sURL; //File URL q'jOI_b
long nStartPos; //File Snippet Start Position ei= 4u'
long nEndPos; //File Snippet End Position j3sz"(
int nThreadID; //Thread's ID 7UBDd1
boolean bDownOver = false; //Downing is over Wet0qt]
boolean bStop = false; //Stop identical 8-G )lyfj
FileAccessI fileAccessI = null; //File Access interface Q6(~VvC-
Y(,RJ&7
M ygCg(h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !~E/Rp
{ IOFXkpKR
this.sURL = sURL; ]xvA2!)Q
this.nStartPos = nStart; I$"Z\c8;
this.nEndPos = nEnd; NO*,}aeG
nThreadID = id; t=7Gfv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vC,FE )'
} 9tpyrGv
ika*w
6[t<g=
public void run() ~ikp'5
{ ?62zv[#
while(nStartPos < nEndPos && !bStop) hrniZ^
{ [+WsVwyf?
mu B Y
XoyxS:=>|[
try{ |lLe^FM
URL url = new URL(sURL); a#1r'z~]}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KGJSGvo+y
httpConnection.setRequestProperty("User-Agent","NetFox"); KF7w{A){
String sProperty = "bytes="+nStartPos+"-"; D*.3]3-I
httpConnection.setRequestProperty("RANGE",sProperty); va@;V+cD
Utility.log(sProperty); ;W{z"L;nX
5j`sJvq
8$-MUF,
InputStream input = httpConnection.getInputStream(); 6Jgl"Jw8
//logResponseHead(httpConnection); j"jssbu}
0Px Hf*
JlSqTfA
byte[] b = new byte[1024]; yD<#Q\,
int nRead; t3$cX_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ytj});,>
{ qBk[Afjgz
nStartPos += fileAccessI.write(b,0,nRead); jZIT[HM
//if(nThreadID == 1) =)bOteWM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ls2OnL9
} @6ckB (
)nHMXZ>Td
MQ =x:p{
Utility.log("Thread " + nThreadID + " is over!"); Z&^vEQ
bDownOver = true; 7Ydqg&
//nPos = fileAccessI.write (b,0,nRead); N)(m^M(~0
} p7+{xXf
catch(Exception e){e.printStackTrace ();} 1 k!gR
} "pt[Nm76)8
} ,q*|R O
\WE/#To
0faf4LzU!
//打印回应的头信息 NL.3qx
public void logResponseHead(HttpURLConnection con) ok--Jyhv#
{ I6WHC*
for(int i=1;;i++) ;FlDRDZ%
{ @IL@|Srs8
String header=con.getHeaderFieldKey(i); y6am(ugE
if(header!=null) Q8HNST($?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0^{Tq0Ri[
Utility.log(header+" : "+con.getHeaderField(header)); YEV;GFI1
else 86%k2~L
break; q!&:y7O8
} N_D=j6B
} g,E)F90
~/4j&IG
~JZLWTEe
public void splitterStop() eZ) |m
{ CMC p7-v
bStop = true; GGHMpQ
} |%4nU#GoB
h(2{+Y+
Gad&3M0r
} []\-*{^r
]UOzz1
MeD/)T{G~
/* ft8
**FileAccess.java ++2a xRl
*//文件访问(定位，写) qw4wg9w5p
package NetFox; o ^w^dgJ
import java.io.*; VIWH~UR)&!
mmFcch$Jv
|x.[*'X@
public class FileAccessI implements Serializable{ J{Ij
mC]Krnx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tklS=R^Vn
RandomAccessFile oSavedFile; k5&}bj-
long nPos; #5;4O{
>Dv=lgPF
H{P*d=9v
public FileAccessI() throws IOException /L,iF?7
{ \(Dm\7Q.
this("",0); $xvwnbq#y
} -XECYwTh
+L?;g pVE&
= r=/L
public FileAccessI(String sName,long nPos) throws IOException B%Oi1bO
{ Uwiy@T Z
oSavedFile = new RandomAccessFile(sName,"rw"); I-s$U T[p
this.nPos = nPos; Md:*[]<~
oSavedFile.seek(nPos); uF,%N
} L-W*h
'e))i#/VF
w#(E+s~}
public synchronized int write(byte[] b,int nStart,int nLen) 9MRe?
{ .Xta;Py|J
int n = -1; cCtd\/ \
try{ qzD
oSavedFile.write(b,nStart,nLen); K(mzt[n(
n = nLen; C/"Wh=h6
} ORo +]9)Yv
catch(IOException e) tchpO3u,
{ MoC/xF&
e.printStackTrace (); 0} \;R5a<
} bB.nevb9p
=Oh/4TbW[
Y$q--JA
return n; K<ldl.
} 0J)VEMC
P`hg*"<V
$I@. <J*
} &)Wm rF
Z;U\h2TY
(B+zh
/* h7\EN
**SiteInfoBean.java ELV$!f|u
*/ +]Bx4r?p
package NetFox; %gEfG#S
+DT)7koA
xI=[=;L
public class SiteInfoBean { /i~n**HeF?
+fF4]WFP
h8SK8sK<
private String sSiteURL; //Site's URL l&Fx< W
private String sFilePath; //Saved File's Path ~i@Z4tj7
private String sFileName; //Saved File's Name (P:.@P~
private int nSplitter; //Count of Splited Downloading File Jxb+NPUB
~f2-%~
YsjTC$Tx,
public SiteInfoBean() 1K$8F ~%Z
{//nSplitter的缺省值为5 47/YDy%
//default value of nSplitter is 5 `WU"*HqW
this("","","",5); 1lUY27MF
} ?6^KY+ 5`C
:'dH)yO
W{'tS{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ! +Hc(i
{ !Ys.KDL
sSiteURL= sURL; x:Tm4V{
sFilePath = sPath; PsMCs|*
sFileName = sName; == i?lbj
this.nSplitter = nSpiltter; dJg72?"ka
0SLn0vD!
EEp,Z`
} ~_L_un.R
G5x%:,n
b!|c:mE9|
public String getSSiteURL() T*C]:=)
{ W[W}:@KZ
return sSiteURL; t5za$kW'&
} 2}R)0][W
?Da!QH >,]
8BJ&"y8H
public void setSSiteURL(String value) 3m`y?Dd
{ [^-DFq5@
sSiteURL = value; RIl+QA
} A0Hsd
G&*2h2,]
H]W59-{a
public String getSFilePath() kO\aNtK
{ SfwAMNCe
return sFilePath; $'VFb=?XrK
} wg,w;Gle
<[GkhPfZ
-i?-Xj#%
public void setSFilePath(String value) |q\:3R_0
{ a2un[$Jq`
sFilePath = value; ]q@6&]9
} J4ltHk.|
|P]>[}mD
viY&D
public String getSFileName() MkG*6A
{ Cc,,e`
return sFileName; rt\4We,7
} h=~TgTv
7fJWb)z!k
1e#}+i!a
public void setSFileName(String value) j!P]xl0vOZ
{ H6XlSj
sFileName = value; t|aBe7t7
} (a i&v
uD''0G\
<J QvuC
public int getNSplitter() g k[8'
{ LN?W~^gsR
return nSplitter; uN1O(s
} =7mn= w?
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!1}A\S
public void setNSplitter(int nCount) xV4 #_1(
{ dw!cDfT+
nSplitter = nCount; _0<EbJ8Z
} /K9Tn
} LMrb 1lg$
X)|b_3Z
um[nz
/* aD@sb o
**Utility.java n15F4DnP
*/ >\ :kP>U
package NetFox; \]W*0t>s
C<\|4ERp
G_~w0r#
public class Utility { g3(fhfR'RN
ayJKt03\O\
M38QA
public Utility() {(#>%f+|C
{ gI qYIt
afcI5w;>}
iy{*w&p
} _kb $S
A-&C.g
//线程睡眠 io$!z=W
public static void sleep(int nSecond) r-+.Ax4L"
{ z17x%jXy
try{ ^[SQw)*
Thread.sleep(nSecond); N4Z%8:"pj
} spV/+jy{
catch(Exception e) .R` {.~_{!
{ eFUJASc
e.printStackTrace (); wTGH5}QZ+
} 61q:nWs
} geL)v7t+#
DKu4e
//日志 8-c1q*q)
public static void log(String sMsg) Bg*Oj)NM
{ }^;Tt-*k
System.err.println(sMsg); %+U.zd$
} ?A/+DRQ(
wG4=[d
QcGyuS.B
public static void log(int sMsg) 1;R1Fj&
{ V6Y:l9
System.err.println(sMsg); |~Hlv^6H
} w^?uBeqR
} T<"Hh.h
R g7 O
s('<ms
/* cWSiJr):r
**TestMethod.java ]VY}VALZ
*/ : uglv6
package NetFox; Rdd[b?
y-gSal
:yo tpa
public class TestMethod { V^WR(Q}
TpLlbsd
-9)<[>:
public TestMethod() ML!Zm[I9
{ ///xx/weblogic60b2_win.exe AXhV#nZt0
try{ :4PK4D s7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "If]qX(w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ixZ w;+h
SiteFileFetch fileFetch = new SiteFileFetch(bean); q[#2`
fileFetch.start(); -(4)lw>U
} 445}Yw5;9
catch(Exception e){e.printStackTrace ();} =#||&1U$
Q<.847 )
b/:&iG;
} x,a(O@
2B{~"<
s_A<bW566F
public static void main(String[] args) /(Se:jH$>
{ %]Gm
new TestMethod(); wiXdb[[#
} 8_6\>hW&
} e#MEDjm/)g
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