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)); ';hU&D;s
} 8E&}+DR?
for(int i=0;i<nEndPos.length-1;i++) o=_:g >5
{ T,@.RF
nEndPos = nStartPos[i+1]; Yewn
} cNtGjLpx;
nEndPos[nEndPos.length-1] = nFileLength; L$cNxz0$
} & 1p\.Y
} Ds9pXgU(Z
]{{A/ j\
N#Y%+1
//启动子线程 h=.|!u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nW3-)Q89
for(int i=0;i<nStartPos.length;i++) pzbR.L}'D
{ 8V>j-C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (8TB*BhQ_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 53J!iNnXT6
nStartPos,nEndPos,i); WW{5[;LYiB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o%i^t4J$e
fileSplitterFetch.start(); PBbJfm
} yQ}$G ,x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7*^-3Tt83
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Bq.@CxK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T1m"1Q
nEndPos = " + nFileLength); "=@b>d6U+
// fileSplitterFetch[nPos.length-1].start(); n.ZLR=P4
8i!AJF9IQ}
L{jJDd
//等待子线程结束 E0'+]"B
//int count = 0; =@AWw:!:,
//是否结束while循环 V&;1n
boolean breakWhile = false; J 05@SG':
Yz=(zj
OXe+=Lp<
while(!bStop) [9(tIb!x
{ gELku .
write_nPos(); N:GSfM@g
Utility.sleep(500); K#rfQ0QK/!
breakWhile = true; OSQZ5:g|
S<rdPS*P
{YC!pDG
for(int i=0;i<nStartPos.length;i++) Ehi)n)HhG"
{ f.JZ[+
if(!fileSplitterFetch.bDownOver) mE'y$5ZxY
{ 0?KXQD
breakWhile = false; -G e5gQ=
break; rZ2X$FO@
} FRd!UqMXY
} (+68s9XS7
if(breakWhile) px %xoY
break; 26PUO$&b.
^E\{&kaUp
Qz\yoI8JA,
//count++; ( NWT/yBx
//if(count>4) L`;p.L Bs_
// siteStop(); 3XF.$=@
} I_6NY,dF
,yus44w[
S-}MS"
System.err.println("文件下载结束！"); fOJ0#^Z
} %tul(Z~<1
catch(Exception e){e.printStackTrace ();} [Oen{c9A
} %KHO}gad1
o(w!x!["
k4fc5P
//获得文件长度 .) uUpY%K^
public long getFileSize() BZejqDr*
{ |z\5Ik!fF]
int nFileLength = -1; F-[zuYGp
try{ 7[h_"@_A7
URL url = new URL(siteInfoBean.getSSiteURL()); XK??5'&{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &[:MTK?x!
httpConnection.setRequestProperty("User-Agent","NetFox"); ;Pf |\q
[ -"o5!0<
gNF8&T
int responseCode=httpConnection.getResponseCode(); F1)B-wW
if(responseCode>=400) =M'M/vKD
{ PLU8:H@X
processErrorCode(responseCode); +^ a9i5
return -2; //-2 represent access is error bP\0S@1YL
} A]ZCQ49
QA>(}u\+
DX GClH
String sHeader; VN[C%C
9qN4f8R
~,+n_KST;
for(int i=1;;i++) YL-/z4g
{ Z?X0:WK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _OV\W'RrA
//Utility.log(in.readLine()); w}No ^.I*4
sHeader=httpConnection.getHeaderFieldKey(i); u$ C@0d
if(sHeader!=null) N`XJA-DE
{ 56gpAc
if(sHeader.equals("Content-Length")) g?`g+:nug
{ .w2QiJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i)9}+M5
break; ;,P-2\V/
} arJ4^ d
} :W]?6=
else L1=3_fO
break; &7Frg`B&:
} AzAD76iNv
} \$:KfN>WY
catch(IOException e){e.printStackTrace ();} Fx,08
catch(Exception e){e.printStackTrace ();} ~f=~tN)hZ
jJFWPD]u
<i{O\K]9
Utility.log(nFileLength); N<lejZ}!q
w1HE^ /
rt">xVl
return nFileLength; 7pMl:\
} 3 i<,#FaL
?xEQ'(UBQ
/~3~Xc~=p
//保存下载信息（文件指针位置） !Ic;;<
private void write_nPos() 4;"^1 $
{ r_C|gfIP
try{ 0\v98g<[+
output = new DataOutputStream(new FileOutputStream(tmpFile)); )006\W|t9
output.writeInt(nStartPos.length); 1Vq]4_09g1
for(int i=0;i<nStartPos.length;i++) lOIBX@K E
{ mr:;Wwd
// output.writeLong(nPos); Yhdt"@;..
output.writeLong(fileSplitterFetch.nStartPos); 1HQh%dZZ
output.writeLong(fileSplitterFetch.nEndPos); _y#omEx
} HT]W2^k
output.close(); H`u8}{7
} ,M2u (9
catch(IOException e){e.printStackTrace ();} A4LGF
catch(Exception e){e.printStackTrace ();} Z$qFjWp
} 3t<XbHF9
U'^AJ2L8
+5J"G/f
//读取保存的下载信息（文件指针位置） 'J^ M`/
private void read_nPos() bwh7.lDAl
{ kN3T/96
try{ tP; &$y.8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )|;*[S4
int nCount = input.readInt(); `nBCCz'Y!
nStartPos = new long[nCount]; `$og]Dn;
nEndPos = new long[nCount]; zNSix!F
for(int i=0;i<nStartPos.length;i++) iVq4&X_x
{ ").MU[q%Y
nStartPos = input.readLong(); *M5: \+
nEndPos = input.readLong(); A ?"(5da.
} _&S?uz m
input.close(); ;>^oe:@
} R=M"g|U6
catch(IOException e){e.printStackTrace ();} 0kN;SSX!
catch(Exception e){e.printStackTrace ();} JA W}]:jC
} blxAy
.G[y^w)w}
,#3}TDC
private void processErrorCode(int nErrorCode) kp3(/`xP
{ _\E{T5
System.err.println("Error Code : " + nErrorCode); /dTy%hZC}
} `5 py6,
(]7*Kq
d,=Kv
//停止文件下载 /lAB
public void siteStop() ?pgdj|"a
{ w:Ui_-4*>
bStop = true; CU=}]Y
for(int i=0;i<nStartPos.length;i++) P.*J'q 28
fileSplitterFetch.splitterStop(); +|.}oL^}G
!_GY\@}
}* iag\
} ?wE@9g A
} \m-fLX
//负责部分文件的抓取 ~~:w^(s9
**FileSplitterFetch.java a%*l]S0z"
*/ ~ILig}I
package NetFox; wu?ahNb.`Y
AH`n
@rs(`4QEh
import java.io.*; ZJ(/cD
import java.net.*; Z=%+U _,
* d6[kY
xGbr>OqkTX
public class FileSplitterFetch extends Thread { "%~\kJ(G
V~LZ%NZ8
eeIh }t>[
String sURL; //File URL x4v@Kk/
long nStartPos; //File Snippet Start Position w+VeT@
long nEndPos; //File Snippet End Position }HS:3Dt
int nThreadID; //Thread's ID ?]gZg[
boolean bDownOver = false; //Downing is over Ke[doQ#c
boolean bStop = false; //Stop identical .(o]d{ '-}
FileAccessI fileAccessI = null; //File Access interface f])?Gw
ZK5(_qW&i
3oX%tx
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H"(:6 `
{ MhC74G
this.sURL = sURL; 0?uX}8w
this.nStartPos = nStart; XfA3Ez,}
this.nEndPos = nEnd; zM6yUEg
nThreadID = id; 70_T;K6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }GvoQ#N
} G%)?jg@EA
U -~%-gFC
*nNzhcuR
public void run() -oq!zi4:
{ A2'
while(nStartPos < nEndPos && !bStop) !f_GR Pj'
{ dJ\6m!Mp
,oe e'
PJj{5,#@3
try{ =/=x"q+X
URL url = new URL(sURL); Ab7hW(/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /uI/8>p(
httpConnection.setRequestProperty("User-Agent","NetFox"); oR}ir
String sProperty = "bytes="+nStartPos+"-"; ulFU(%&
httpConnection.setRequestProperty("RANGE",sProperty); o;Ijv\Em
Utility.log(sProperty); 4W8rb'B!Ay
|Hn[XRsf
q!W~>c!
InputStream input = httpConnection.getInputStream(); 1!8*mk_R{
//logResponseHead(httpConnection); 20m6-rkI<}
P Y +~,T2
"@B!5s0
byte[] b = new byte[1024]; Wm:3_C +j
int nRead; Pb?H cg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mm$D1=h{|
{ YVVX7hB
nStartPos += fileAccessI.write(b,0,nRead); 7ka^y k@Q
//if(nThreadID == 1) i]GBu
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !s,<hU#
} c5P52_@
R7*Jb-;$!
Wq)'0U;{$
Utility.log("Thread " + nThreadID + " is over!"); 1=#r$H
bDownOver = true; $oE 4q6b
//nPos = fileAccessI.write (b,0,nRead); ~l!(I-'?g
} o^RdVSkU;
catch(Exception e){e.printStackTrace ();} <mHptgd,
} L1BpkB
} LoHWkNZ5:
uuj"Er31
gT @YG;
//打印回应的头信息 IcL3.(!]l
public void logResponseHead(HttpURLConnection con) Wy#`*h,
{ ->wY|7
for(int i=1;;i++) ;]fpdu{
{ hgj#VY$B
String header=con.getHeaderFieldKey(i); j>&n5?
if(header!=null) 567ot|cc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5!#"8|oY
Utility.log(header+" : "+con.getHeaderField(header)); el!Bi>b9c!
else w|WZEu:0|
break; A`(p6 H"s
} V$ 38
} *wt yyP@
/iif@5lw{
+Smv<^bW
public void splitterStop() |}Mkn4
{ sxL;o>{
bStop = true; 4\pA^%73
} d1e'!y}R5
&o"Hb=k<
}=A6Jv(j
} QXJD'c
ZC"6B(d
]+0-$t7Y
/* +^YV>;
**FileAccess.java _if&a'
*//文件访问(定位，写) ?y<n^`
package NetFox; XeDU ,
import java.io.*; I#eIm3Y?
R,Zuy(g
hPr
public class FileAccessI implements Serializable{ #!#V!^ o
d\;M F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dMGu9k~u
RandomAccessFile oSavedFile; 3\=8tg p
long nPos; HKOJkbVZ2^
vlIdi@V
^'EEry
public FileAccessI() throws IOException ^\N2 Iu>6
{ D\({]oj]
this("",0); >[|:cz
} R5]R pW=G
%h|z)
#PXl*~PrQ/
public FileAccessI(String sName,long nPos) throws IOException |D]jdd@!a2
{ q4Ye
oSavedFile = new RandomAccessFile(sName,"rw"); |<y[gj4`T/
this.nPos = nPos; KH pxWq
oSavedFile.seek(nPos); KXw \N!
} um,/^2A
N)poe2[
/2'\ya4B
public synchronized int write(byte[] b,int nStart,int nLen) nr&G4t+%Hv
{ z*yN*M6t
int n = -1; u"T5m
try{ 9k7|B>LT
oSavedFile.write(b,nStart,nLen); e}[$ =
n = nLen; }QJE9;<e
} Slv}6at5
catch(IOException e) ~fCD#D2KU
{ -HoPECe
e.printStackTrace (); J=zZGd%
} 8w2+t>?
?9?0M A<[i
X0vkdNgW
return n; &)s A(
} SNK+U"Q
AZl=w`;/O%
Q|5wz]!5Y(
} (|U+(~PJ
Y}1|/6eJ
&OI=rvDmo
/* .\U+`>4av
**SiteInfoBean.java ZLL0 6p
*/ Nq*\{rb
package NetFox; qk_ s"}sS
bO2$0!=I
k9^P#l@p
public class SiteInfoBean { $%1[<}<
Q8:u1$}
U +mx@C_
private String sSiteURL; //Site's URL ' J-(v
private String sFilePath; //Saved File's Path _|A)ueY
private String sFileName; //Saved File's Name Z]SCIU @+
private int nSplitter; //Count of Splited Downloading File Nm,vE7M
<[~x]-
Hlz4f+#I
public SiteInfoBean() +!_^MBkk
{//nSplitter的缺省值为5 :eIBK
//default value of nSplitter is 5 !5A nr
this("","","",5); W{-N,?z
} f2{4Y)
}WCz*v1Wq
(Mtc&+n{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~Zj?%4
{ h+Q==
sSiteURL= sURL; 0A1l"$_|
sFilePath = sPath; kN}.[enI~
sFileName = sName; l>=c]
this.nSplitter = nSpiltter; R8],}6,;E}
zb;'}l;+
4&y_+
} r`S]`&#}(
j ^_G
Szg<;._J
public String getSSiteURL() #Jm_~k
{ '|]zBpz
return sSiteURL; |fw+{f
} 5n9F\T5
sWX
3}h&/KN{
public void setSSiteURL(String value) a#raUF7e
{ 'm2,7]
sSiteURL = value; *K+*0_
} G %#us3x
F5MWxAS,>
s#d# *pgzh
public String getSFilePath() ZnJnjW PQ
{ x(t}H8q
return sFilePath; '6xn!dK
} ^MddfBwk
=} vG|
x%(!+
public void setSFilePath(String value) ikxSWO_Y=
{ ~Yr.0i.W
sFilePath = value; (>8fcQUBb
} N@A#e/8
F8=6!Qj
G4RsH/
public String getSFileName() Ko%rB+d
{ qlgh$9
return sFileName; Uc6U!X
} R/b=!<
2#E;5UYu
*=sU+x&X
public void setSFileName(String value) 1i>)@{P&BN
{ UWusSi3+LG
sFileName = value; gq0gr?
} ~(&xBtg:}
jWoo{+=D
P{qn@:
public int getNSplitter() Zv-6H*zM6
{ k,@1rOf
return nSplitter; Cu?$!|V
} tP:xx2N_
DX!$k[
6g.@I!j E
public void setNSplitter(int nCount) ?.Kl/8ml
{ >eEf|tKO
nSplitter = nCount; FCP5EN
} A{c6XQR~z
} |BW956fBU
}YSH8d
Qy$QOtrv
/* -[7.VP
**Utility.java p5[uVRZ
*/ -!}1{
package NetFox; 1u`Z?S(
%idnm
@=,J6
public class Utility { $"UAJ-
T }8aj
.K93VTzy
public Utility() 0SDCo\
{ 9rid98~d
q OXL(
m0#hG x
} w%ip"GT,
7dakj>JM
//线程睡眠 C9nNziws
public static void sleep(int nSecond) z^b\hR
{ x``!t>)O
try{ 1";~"p2(
Thread.sleep(nSecond); O^<6`ku
} P9'5=e@jB
catch(Exception e) <T}#>xHs3
{ O:U@m@7
e.printStackTrace (); \vT8 )\
} m&%N4Q~X>
} m:^@AR1%d
H}$#aXEAn
//日志 T8\,2UWsj2
public static void log(String sMsg) %sq=lW5R{b
{ _<~05Eh
System.err.println(sMsg); '0=U+Egp
} 4 '+)9&g
~W#f,mf
J)-owu;
public static void log(int sMsg) 7]^Cg;EtM:
{ *\`C!r
System.err.println(sMsg); jsG9{/Ov3
} %z2nas$$g
} p!691LI
O3_Mrn(R
!of7]s
/* jab]!eY
**TestMethod.java X-duG*~
*/ H{V-C_
package NetFox; e,x@?L*
oO|^ [b#
Q,4F=b
public class TestMethod { QZfPd\Q5
mA."*)8VNg
@Yg7F>s
public TestMethod() ::R^ w"
{ ///xx/weblogic60b2_win.exe a} /Vu"
try{ jn7}jWA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $-y+97
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Uyh
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^U =`Rx
fileFetch.start(); !Q#b4f
} l:ED_env:
catch(Exception e){e.printStackTrace ();} _5)#{o<
AVJk
GGBe/X
} a~%ej.)l
d!d 3r W;A
^Y&Cm.w
public static void main(String[] args) ^d"J2n,7L
{ .$yw;go3
new TestMethod(); Q\oUZnD$=
} }}2kA
} 5A)w.i&V
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