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)); JO|%Vpco
} !foiGZ3g
for(int i=0;i<nEndPos.length-1;i++) DlD;rL=
{ m2i'$^a#
nEndPos = nStartPos[i+1]; 1FkS$ j8:
} e-4 Qw#cw
nEndPos[nEndPos.length-1] = nFileLength; &bIE"ZBjt
} LqDj4[}
} W7\s=t\
ji8)/
T>$S&U
//启动子线程 ^ UB*Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &jbZL5
for(int i=0;i<nStartPos.length;i++) (IE\}QcK
{ *$+:Cbe-F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ><l|&&e-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;J]Lzh
nStartPos,nEndPos,i); Eku+&f@RB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I1J/de,u
fileSplitterFetch.start(); 8p91ni'
} bL6, fUS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <Qx]"ZP%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Hzn6H4Rc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R6xJw2;_
nEndPos = " + nFileLength); !4?QR
// fileSplitterFetch[nPos.length-1].start(); y3^>a5z!x
acPX2B[jJ
D|8Pe{`
//等待子线程结束 r+yl{
//int count = 0; $G,#nh2 oD
//是否结束while循环 (8XP7c]5
boolean breakWhile = false; x/)o'#d$|l
U?WS\Jji3!
%UO ;!&K
while(!bStop) /x2MW5H
{ 4ayZ.`aK
write_nPos(); ;7 F'xz"
Utility.sleep(500); Klv~#9Si
breakWhile = true; JX $vz*KF
Qf$3!O}G
1(nK|
for(int i=0;i<nStartPos.length;i++) oh@|*RU
{ #mFY?Zp)
if(!fileSplitterFetch.bDownOver) YXFUZ9a#e
{ axpn*(yE
breakWhile = false; ,cF $_7M
break; JvI6+[
} 'Cq)/}0
} C7hJE-
if(breakWhile) >EJ`Z7E6
break; "QV?C
ZD`9Ez)5
(Y[q2b
//count++; DO5H(a
//if(count>4) dyyGt}}5f
// siteStop(); k~|5TO
} /Y7YyjMi
~4}'R_
8b!-2d:*
System.err.println("文件下载结束！"); f:!b0j
} U~nW>WJ+.
catch(Exception e){e.printStackTrace ();} m7n8{J1O2
} EPn0ZwnS:M
Ra~|;( %d
{~=Z%Cj2Q
//获得文件长度 BT3X7Cx
public long getFileSize() (G#QRSXc\
{ s2N~p^
int nFileLength = -1; 1P '_EJ]M
try{ 9Z_!}eY2mc
URL url = new URL(siteInfoBean.getSSiteURL()); Dau'VtzN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s6F^z\6
httpConnection.setRequestProperty("User-Agent","NetFox"); O"c@x:i
ymr#OP$<S
Xb'UsQ
int responseCode=httpConnection.getResponseCode(); d8V)eZYXy~
if(responseCode>=400) uY"Bgz:=d
{ aEJds}eE6)
processErrorCode(responseCode); nUy2)CL[L
return -2; //-2 represent access is error K3xs=q]:@
} e ab_"W
y wf@G; fK
~V:@4P
String sHeader; Xv2u7T\
Lfj]Y~*z
JIYZ
for(int i=1;;i++) Q9C;_Up
{ X1J'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8h=Rfa9
//Utility.log(in.readLine()); @*s7~:VQ
sHeader=httpConnection.getHeaderFieldKey(i); '4x uH3
if(sHeader!=null) wFHz<i!jr&
{ ta)'z@V@g
if(sHeader.equals("Content-Length")) !}$,) ~<+H
{ oDvE0"Sz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FsXqF&{
break; N:]Ud(VRM
} 3R|C$+Sc
} lA1l
else `VzjXJw
break; ybNy"2Wk
} ^|+;~3<J
} 12bt\h9
catch(IOException e){e.printStackTrace ();} 6%8,OOS
catch(Exception e){e.printStackTrace ();} `&rt>Bk /
gb,X"ODq
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Utility.log(nFileLength); DFUW^0N
3ug-cq
_w\A=6=q|
return nFileLength; =Kh1HU.F
} ' 6#en9{L
Kz`g Q|S
UrhSX!g/A>
//保存下载信息（文件指针位置） pZA0Go2!IN
private void write_nPos() MPxe|Wws
{ h+<F,0
try{ {:!CA/0Jx
output = new DataOutputStream(new FileOutputStream(tmpFile)); nTd[-3o
output.writeInt(nStartPos.length); wFHbz9|@I
for(int i=0;i<nStartPos.length;i++) #y4+O;{
{ Ki_8g
// output.writeLong(nPos); O*%@(w6
output.writeLong(fileSplitterFetch.nStartPos); ',g'Tl^E
output.writeLong(fileSplitterFetch.nEndPos); <8_~60
} pk&;5|cCD
output.close(); 3%'Y):
} <JyF5
catch(IOException e){e.printStackTrace ();} d4]9oi{}
catch(Exception e){e.printStackTrace ();} w]ZE('3%W
} k:JlC(^h
&qO#EEqG]
O 6}eV^y
//读取保存的下载信息（文件指针位置） 2&+Nr+P
private void read_nPos() ^o@N.+`&<
{ u#&ZD|
try{ Vw~st1",[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wm<`0}
int nCount = input.readInt(); / ~\ I
nStartPos = new long[nCount]; m+7/ebj{A
nEndPos = new long[nCount]; W? ^ ?Kx
for(int i=0;i<nStartPos.length;i++) 2U Q&n`A
{ F=qG+T
nStartPos = input.readLong(); 0zCmU)ng
nEndPos = input.readLong(); l2lyi
} 6k@(7Mw8A
input.close(); e71dNL'$
} btV Tt5
catch(IOException e){e.printStackTrace ();} nR2pqaKc
catch(Exception e){e.printStackTrace ();} lz-t+LD@ST
} :w+2L4lGs
]LE
'Rg6JW\
private void processErrorCode(int nErrorCode) "Om4P|
{ `1T?\
System.err.println("Error Code : " + nErrorCode); (Q/Kp*a
} g=gWkN <
)PNeJf|@
i7UE9Nyl*
//停止文件下载 AzmISm
public void siteStop() fZH";_"1
{ 2 u{"R
bStop = true; {ejJI/o0
for(int i=0;i<nStartPos.length;i++) pg4J)<t#
fileSplitterFetch.splitterStop(); 7 z#Xf
,8vqzI
P`$"B0B)
} (i"@{[IP
} p903*F^[,
//负责部分文件的抓取 uoIvFcb^
**FileSplitterFetch.java Y9K$6lz
*/ 0bt"U=x4
package NetFox; vp>,}nx4
VX`E7Sf!}
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import java.io.*; fF"\$Ny
import java.net.*; aUBGp: (
64hl0'67y
z'(][SB
public class FileSplitterFetch extends Thread { Ca?:x tt
aIA9rn
O$2'$44HX
String sURL; //File URL h)MU^aP
long nStartPos; //File Snippet Start Position w[A$bqz
long nEndPos; //File Snippet End Position @ z{E
int nThreadID; //Thread's ID e{~3&
boolean bDownOver = false; //Downing is over NFEF{|}BM
boolean bStop = false; //Stop identical xjplJ'jB
FileAccessI fileAccessI = null; //File Access interface wTL&m+xr
6^Q Bol
BfcpB)N&.K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qNH= W?T8.
{ bK7j"
this.sURL = sURL; CflGj0oy8
this.nStartPos = nStart; ~Lyy7B9
this.nEndPos = nEnd; xw)$).yc
nThreadID = id; h{R>L s
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :dZq!1~t
} }! jk
}AZ0BI,TI
tY1M7B^~
public void run() z^KMYvH g
{ rfl-(_3
while(nStartPos < nEndPos && !bStop) ^RS?y8
{ }i"\?M
ZW6ZO[`6
(sXR@Ce$
try{ aQMUC6cPM@
URL url = new URL(sURL); 3XCePA5z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H\zV/1~Y
httpConnection.setRequestProperty("User-Agent","NetFox"); wNHvYulI
String sProperty = "bytes="+nStartPos+"-"; P|>pm]>C
httpConnection.setRequestProperty("RANGE",sProperty); N,iYUM?
Utility.log(sProperty); YH0=YmU#X
yBd#*3K1
th$?#4SbR
InputStream input = httpConnection.getInputStream(); yJ\K\\]
//logResponseHead(httpConnection); {hS9FdWA;
q&j4PR{
yXuF<+CJ
byte[] b = new byte[1024]; 0Y%u[i/
int nRead; %Km^_JM
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qmWK8}F.cE
{ D*Cn!v$
nStartPos += fileAccessI.write(b,0,nRead); #6'x-Z_
//if(nThreadID == 1) |>/T*zk<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r#%e$
} @w8MOT$
w^_[(9 `
2|LgUA?<
Utility.log("Thread " + nThreadID + " is over!"); |#y+iXTJ
bDownOver = true; cc*xHv^
//nPos = fileAccessI.write (b,0,nRead); }mZsK>
} zA~aiX
catch(Exception e){e.printStackTrace ();} :`pgdn
} ]vFtByqn
} 6X2~30pdE
\:'|4D]'I
%ut^ O
//打印回应的头信息 0R#T3K}
public void logResponseHead(HttpURLConnection con) qu}&4_`%:V
{ &Z.zem?n
for(int i=1;;i++) P?.j wI
{ #QWG5
String header=con.getHeaderFieldKey(i); "_g3{[es!
if(header!=null) Id<3'ky<N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?qdZ]M4e
Utility.log(header+" : "+con.getHeaderField(header)); |#87|XIJ&~
else SR+<v=i
break; \Y>!vh X
} %[ Z[
} i*T>,z
&fyT}MA
j06Xz\c
public void splitterStop() &!adW@y
{ ggy 7p44
bStop = true; |JR;E$
} f&n6;N
p^E}%0#
-F]0Py8(
} JfrPK/Vn
,X&(BQj h
#fuc`X3:HL
/* 4!I;U>b b
**FileAccess.java SEL7,8 Hm
*//文件访问(定位，写) jn+M L&
package NetFox; h=1cD\^|qw
import java.io.*; kOQq+_Y
"I7 Sed7
x}c%8dO#J
public class FileAccessI implements Serializable{ _w'N&#
",pN.<F9O
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 UTThl2=+
RandomAccessFile oSavedFile; {eQ')f
long nPos; Q)H1\
PCx] >&
Xyf7sHQ
public FileAccessI() throws IOException ^EG@tB $<
{ .t7mTpi
this("",0); h/AL`$
} ]h`<E~
Wl4T}j
_i-(`5
public FileAccessI(String sName,long nPos) throws IOException s-z*Lq*
{ L, k\`9bQ
oSavedFile = new RandomAccessFile(sName,"rw"); p?#cn
this.nPos = nPos; }'FNGn.~#
oSavedFile.seek(nPos); .ZB/!WiF
} jW?siQO^
b')Lj]%;k
p{sbf;-x}
public synchronized int write(byte[] b,int nStart,int nLen) Ga%x(1U[&
{ '%D$|)
int n = -1; Qxvj`Ge
try{ +yh-HYo`
oSavedFile.write(b,nStart,nLen); pO;BX5(x
n = nLen; y'a(>s(
} WC?}a^ 8
catch(IOException e) !JkH$~
{ 0UHX Li47Y
e.printStackTrace (); :=0XT`iY
} :*{>=BD
x+L G4++
R m{\ R
return n; 2Sq+w;/
} LPOZA`
$p} /&
s`bC?wr5h
} 49BLJ|:P?
q$;'Fy%oy
L 1fK
/* Od>^yhn
**SiteInfoBean.java CD]2a@j{
*/ ic"n*SZa
package NetFox; )LA^j|Y}
Qe~2'Hw#9
Rv ]?qJL
public class SiteInfoBean { ]wMp`}$b@L
%PsDS
~okIiC]#
private String sSiteURL; //Site's URL `%2e?"OOJ
private String sFilePath; //Saved File's Path x bG'![OX
private String sFileName; //Saved File's Name ^GXy:S$
private int nSplitter; //Count of Splited Downloading File ZUvA`
3b_tK^|'
J.`z;0]op
public SiteInfoBean() !eoN
{//nSplitter的缺省值为5 S;o U'KOY
//default value of nSplitter is 5 E0nR Vg
this("","","",5); cU y,q]PO
} /nK)esB1L
*>=vSRL0_
n0X_m@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nP9@yI*7
{ }OeEv@^
sSiteURL= sURL; Tl#Jf3XY}
sFilePath = sPath; C?n3J
sFileName = sName; 2$D *~~
this.nSplitter = nSpiltter; WC!bB
Y$^x.^dT,
)shzJ9G
} -R!qDA"
SL;\S74
lu^c^p;
public String getSSiteURL() lN,8(n?g
{ *yuw8
return sSiteURL; GHHErXT\a
} 2Yx6.e<
o7feH 6Sh
/j]r?KAzw
public void setSSiteURL(String value) qO
{ %h**L'~``
sSiteURL = value; =&*:)
} ]JX0:'x^
Q6y883>9
<zN
public String getSFilePath() k]<
{ 3G9YpA_}X
return sFilePath; ?~rF3M.=|
} }DTpl?l
3,j)PKf ;
^4Ra$<
public void setSFilePath(String value) 'sJ=h0d_[V
{ (Rvke!"B
sFilePath = value; (NUk{MTX
} w,NK]<dU@
pb`F_->uq
rt%.IQdY
public String getSFileName() XG"&\FL{T
{ >9W ;u`
return sFileName; C #ng`7 q
} @<--5HbX
/%Bc*k=ox
"U34D1I)#
public void setSFileName(String value) ]Ff"o7gT
{ SMaC{RPQ
sFileName = value; euM7> $`
} Qi|jL*mj&
Vg/{;uLAe
s+>""yi
public int getNSplitter() /-<S FT`
{ 2%N$Y]
return nSplitter; SF61rm
} qUSImgg
I#Ay)+D
KzZ! CB\
public void setNSplitter(int nCount) Y((s<]7
{ x^}kG[s
nSplitter = nCount; w4pU^&O
} L,.Ae i9
} DF'-dh</*
AJSe +1
!<]%V]5[_
/* Mw@T!)(
**Utility.java oju7<b9Ez
*/ ^AMcZ6!\
package NetFox; 0\%/:2
8Cz_LyL
+T=Z!2L
public class Utility { ?U~C= F?K
?hvPPEJf
9_[TYzpB!
public Utility() c|u{(E58
{ (E59)z -
bLGgu#
/HgdTyR)
} 4&)*PKq
%TdZ_
//线程睡眠 314PcSc
public static void sleep(int nSecond) =v=a:e
{ :L&Bbw(
try{ V(1Ldl'a
Thread.sleep(nSecond); !HL7a]PB
} k_#ra7zP
catch(Exception e) gxpR#/(E~
{ \-N 4G1
e.printStackTrace (); P%f],f
} eX7Ev'(H
} <",4O
[sp=nG7i&
//日志 .2/(G{}U
public static void log(String sMsg) L=3^A'|
{ "0 \U>h
System.err.println(sMsg); T j9;".
} X{\>TOk
6c>t|=Ss(
RK#e7
public static void log(int sMsg) P!:Y<p{=>
{ o0&jel1a
System.err.println(sMsg); 5:E7nqsNhq
} @FIR9XJ
} |1X^@
]78I
x0@J~ _0
/* "12.Bi.O"[
**TestMethod.java /ZHuT=j1
*/ HT)b3Ws~M8
package NetFox; ;H/*%2
7g}4gX's
xcwyn\93)
public class TestMethod { hL~@Ah5&t
T5.1qrL
_$PZID
public TestMethod() @|(mR-Jj
{ ///xx/weblogic60b2_win.exe frbKi _1
try{ u*Z>&]W_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H`CDfTy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BusD}9QqB
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~'KymarPU
fileFetch.start(); [?iA`#^d
} /cF 6{0XS9
catch(Exception e){e.printStackTrace ();} 2MQgTFM9
&!]$#
5s_7P"&H
} _Sy-&}c+ +
z:-a7_
Ac'[(
public static void main(String[] args) wv<D%nF2|
{ D% }?l
new TestMethod(); )9MmL-7K
} (xpj?zlmM
} >[B}eS>
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