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)); D,hl+P{^K
} 6?_Uow}
for(int i=0;i<nEndPos.length-1;i++) ;02lmpBj
{ ?eu=0|d
nEndPos = nStartPos[i+1]; 4_mh
} .,c8cq?
nEndPos[nEndPos.length-1] = nFileLength; K|B1jdzL
} PQfx0n,
} {>z.y1
$exu}%
F :u}7t>
//启动子线程 Rl,B !SF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +`[$w<I
for(int i=0;i<nStartPos.length;i++) `S!`=26Z!
{ ';1 c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !{4p+peqJV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YB 4R8}4
nStartPos,nEndPos,i); ZFRKh:|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9@h>_1RJz
fileSplitterFetch.start(); y,%w`
} nK:39D$(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 04(h!@!g:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $)'{+1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7mu%|!
nEndPos = " + nFileLength); DF|qNX
// fileSplitterFetch[nPos.length-1].start(); We" "/X
"aP/214Ul
kh`X92~
//等待子线程结束 r2Q"NVw
//int count = 0; J)R2O4OEd
//是否结束while循环 o?b"B+#
boolean breakWhile = false; t >8t|t+
@50Js3R1q
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while(!bStop) <cl$?].RE!
{ rp _G.C
write_nPos(); A$-{WN.W
Utility.sleep(500); xd>2TW l#
breakWhile = true; t rHj7Nw
HHX9QebiST
QJv,@@mu
for(int i=0;i<nStartPos.length;i++) %~6+=*(\
{ D0(gEb
if(!fileSplitterFetch.bDownOver) /WM : Bj
{ 87*R#((
breakWhile = false; au GN~"n^
break; {2V=BDS|?K
} {t9U]hX%A[
} %2>FSE
if(breakWhile) '2%hc\P6P
break; s_RYYaM
5uu{f&?u)
(+4=A k
//count++; /1O6;'8He
//if(count>4) K<V(h#(.@
// siteStop(); %';n9M
} q6osRK*20
Ron^PvvY&
%.Mtn%:I*
System.err.println("文件下载结束！"); A^g81s.5
} >(\[$
catch(Exception e){e.printStackTrace ();} S46[2-v1
} y{kXd1,
Qi[T!1
U:`rNHl
//获得文件长度 Bw{W-&$o
public long getFileSize() BURiLEYZl
{ ?lbX.+
int nFileLength = -1; u_mm*o~)g
try{ k5<lkC2z
URL url = new URL(siteInfoBean.getSSiteURL()); h; {?z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !4 6^}3
httpConnection.setRequestProperty("User-Agent","NetFox"); 2Y$==j
J,IOp-
Q9rE_}Z
int responseCode=httpConnection.getResponseCode(); 2wu 5`Z[E
if(responseCode>=400) FxD"z3D
{ YP#OI6u
processErrorCode(responseCode); );=JoRQ{
return -2; //-2 represent access is error 71wyZJ
} Ef7Kx49I
sX@e1*YE_
M`"2;
String sHeader; +LrW#K;
{\ .2h
/oWB7l&
for(int i=1;;i++) Q>||HtF$A
{ M?]ObIM:5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6Q\n<&,{
//Utility.log(in.readLine()); !(+?\+U lE
sHeader=httpConnection.getHeaderFieldKey(i); {9P<G]Z
if(sHeader!=null) 1tg
{ 2Q<_l*kk(
if(sHeader.equals("Content-Length")) `M\L6o
{ }~\J7R'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lJq %me;4m
break; `.><$F
} bv|v9_i
} 5*ABw6'6
else =. OWsFv
break; CuDU~)`
} .t\Yv/|`
} {_Wtk@
catch(IOException e){e.printStackTrace ();} .o fYFK
catch(Exception e){e.printStackTrace ();} Kz'W |
C10A$=!
.i`+}@iA
Utility.log(nFileLength); W;j*lII
3{,Mpb@
UIzk-.<
return nFileLength; _*&<hAZj
} W6]iJ
GY0<\-
N[=nh)m7b
//保存下载信息（文件指针位置） nEs l
private void write_nPos() ,![C8il,
{ g[!sGa&
try{ Be?mIwc_g
output = new DataOutputStream(new FileOutputStream(tmpFile)); qOkw6jfluh
output.writeInt(nStartPos.length); drF"kTD"7
for(int i=0;i<nStartPos.length;i++) 6eQrupa
{ s2&UeYbIs
// output.writeLong(nPos); Hs2L$TX
output.writeLong(fileSplitterFetch.nStartPos); w)3LYF
output.writeLong(fileSplitterFetch.nEndPos); |RHX2sso
} mnG\UK,k
output.close(); \b~zyt6-
} %K?~$;Z.
catch(IOException e){e.printStackTrace ();} TS@EE&Wq
catch(Exception e){e.printStackTrace ();} [gD02a:u
} R?^FO:nM%!
u!;kBs
2{ }5WH
//读取保存的下载信息（文件指针位置） XBi@\i=
private void read_nPos() +U@P+;
{ C\EZ8
try{ Zni8im,_j
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0p&:9|'z
int nCount = input.readInt(); -.:1nI
nStartPos = new long[nCount]; *$uKg zv3
nEndPos = new long[nCount]; |+ @
for(int i=0;i<nStartPos.length;i++) awo=%vJ&
{ Sd}fse
nStartPos = input.readLong(); (r:WG!I,
nEndPos = input.readLong(); b-%7@j
} x4Eq5"F7}
input.close(); -N*g|1rpa
} #P18vK5
catch(IOException e){e.printStackTrace ();} ^#XxqVdPk
catch(Exception e){e.printStackTrace ();} &#`d8}3D
} @v@'8E Q
V/J[~mN9
\-`L}$
private void processErrorCode(int nErrorCode) sK}Ru?a)
{ 9JP{F
System.err.println("Error Code : " + nErrorCode); pO=bcs8Z
} UV@<55)K
z{;W$SO 2
C n4|qX"&t
//停止文件下载 Sr%~ 5Q[W
public void siteStop() eBtkTWx5[/
{ wf<uG|90
bStop = true; Oj~k1+*
for(int i=0;i<nStartPos.length;i++) ApjLY58=
fileSplitterFetch.splitterStop(); E=HS'XKu[K
vqv(KsD+::
Xgr|~(^
} v;jrAND
} xLq+njH E
//负责部分文件的抓取 ;k(|ynXv
**FileSplitterFetch.java -&@[]/
*/ 5N`g
package NetFox; />.&
|oPqX %?
t[)z/[m
import java.io.*; |`_TVzA
import java.net.*; =@w};e#D
||9f@9
aN%t>*?Xa
public class FileSplitterFetch extends Thread { 5j,)}AYO
plb'EP>e
ur9-F^$
String sURL; //File URL E(8O3*=
long nStartPos; //File Snippet Start Position ra$_#HY
long nEndPos; //File Snippet End Position ,Sghi&Ky
int nThreadID; //Thread's ID {l\v J#r:
boolean bDownOver = false; //Downing is over @b-?KH
boolean bStop = false; //Stop identical 7o0ej#
FileAccessI fileAccessI = null; //File Access interface :t^=~xO9
+ +D(P=4hi
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q35%t61Lc
{ LvhF@%(9J
this.sURL = sURL; Hagj^8
this.nStartPos = nStart; BYNOgB1
this.nEndPos = nEnd; B~LB^ n(>@
nThreadID = id; oV,>u5:B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gaTI:SKzc
} @*A(#U8p3
)x?F1/
~wh8)rm
public void run() $].< /
{ `'+[Y;s_
while(nStartPos < nEndPos && !bStop) ^9qncvV
{ vnXpC!1
#HM0s~^w&
X B65,l
try{ tUz!]P2BUO
URL url = new URL(sURL); )5'S=av9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J=zh+oLCV
httpConnection.setRequestProperty("User-Agent","NetFox"); -`f JhQ|
String sProperty = "bytes="+nStartPos+"-"; ;h0?o*i_
httpConnection.setRequestProperty("RANGE",sProperty); @i6D&e=
Utility.log(sProperty); CNfeHMT
Q9FY.KUM
Gq+!%'][P
InputStream input = httpConnection.getInputStream(); i#(T?=VPcy
//logResponseHead(httpConnection); #sAEIk/
7&l
_2U1$0xK
byte[] b = new byte[1024]; 0'RSl~QvqS
int nRead; |w:7).P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IjJ3CJ<
{ "sL#)<%
nStartPos += fileAccessI.write(b,0,nRead); YujhpJ<
//if(nThreadID == 1) 9K FWa0G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YX@[z 5*
} -DU[dU*~
Rz*%(2Vz
l(%bdy
Utility.log("Thread " + nThreadID + " is over!"); 5Lm ?
bDownOver = true; ^om(6JL2
//nPos = fileAccessI.write (b,0,nRead); el-%#0
} U,aV{qz
catch(Exception e){e.printStackTrace ();} Be0P[v
} /':kJOk<[
} mA3C)V
RUSBJsMB
M2vYOg`t:c
//打印回应的头信息 pPeS4$Y
public void logResponseHead(HttpURLConnection con) CbI[K|
{ L[Tr"BW
for(int i=1;;i++) AGS?<6W-
{ 5wiU4-{
String header=con.getHeaderFieldKey(i); g2w0#-
if(header!=null) ^MQ7*g6o
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &kYg >X
Utility.log(header+" : "+con.getHeaderField(header)); W@#)8];>
else G|IO~o0+
break; vezX/xD?
} 1Cp5a2{
} ^Shz[=fd
>$?$&+e}
6\/C]![%
public void splitterStop() V= !!;KR0
{ $(.[b][S
bStop = true; Lc0^I<Y
} l;F3kA
-~]*)&
Th'6z#h:U
} K7U`
=<n+AqJ%
OUS@)Tyh
/* ;~#rdL
**FileAccess.java N[z7<$$
*//文件访问(定位，写) K"#np!Y)
package NetFox; ^)D[ W(*
import java.io.*; \C~Y
d%u|) =7
8u!!a^F
public class FileAccessI implements Serializable{ !T#~.QP4
wh[XJ_xY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V)f/umT%g
RandomAccessFile oSavedFile; W;eHDQ|
long nPos; [8(e`6xePb
%Z}A+Rv+*m
g75)&U`>}
public FileAccessI() throws IOException pg [F{T<
{ |!aMj8i2
this("",0); uIiE,.Uu}
} S XIo
\%K< S
0ua.aL'
public FileAccessI(String sName,long nPos) throws IOException #t>w)`bA-
{ =*~]lz__M
oSavedFile = new RandomAccessFile(sName,"rw"); :1PT`:Y
this.nPos = nPos; \|L ~#{a
oSavedFile.seek(nPos); ^} %OqP
} #9F=+[L
W}50E.\#
4'cdV0]
public synchronized int write(byte[] b,int nStart,int nLen) ^dJ/>?1
{ WSz#g2a
int n = -1; 4nN%5c~=
try{ cz~Fz;)2{N
oSavedFile.write(b,nStart,nLen); "M3R}<Vt
n = nLen; Jlj=FA`
} :,h47'0A
catch(IOException e) }S\\"SBC
{ Gg]>S#^3
e.printStackTrace (); /. k4Y
} 6FFQoE|n
8$xd;+`y'
F4xYfbwY"]
return n; "94e-Nx
} E:a_f!
$!h21
] lE6:^V
} ]?whx&+
}1=V`N(
W3Oj6R
/* ~Gx"gK0
**SiteInfoBean.java ebxpKtEC
*/ o?BcpWp
package NetFox; kq&xH;9=.
j qfxQ
vPz$jeA
public class SiteInfoBean { d:cs8f4>
5v >0$Y{
1$2'N~`#U
private String sSiteURL; //Site's URL L 1iA ^x
private String sFilePath; //Saved File's Path 6c>cq\~E
private String sFileName; //Saved File's Name 4iMo&E<
private int nSplitter; //Count of Splited Downloading File ^Tgu]t
_+73Y'
\wwY?lOe
public SiteInfoBean() -T3 z@k
{//nSplitter的缺省值为5 pB*8D
//default value of nSplitter is 5 pxy=edd
this("","","",5); VSns_>o
} |+K3\b
@Cg%7AF
Z3X/SQ'0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mhU ?N
{ [*^`rQ
sSiteURL= sURL; k@vN_Un
sFilePath = sPath; Z&BJ/qk \-
sFileName = sName; HQqnJ;ns<
this.nSplitter = nSpiltter; 7L2$(d4
;n1<1M>!
9+><:(,
} j_YpkKhen
H809gm3(Z
<=D!/7$O
public String getSSiteURL() 2UqLV^ZY
{ Z{&dzc
return sSiteURL; "*E06=fiG
} 3,;;C(
JAEn 72
hdW}._
public void setSSiteURL(String value) 'VVEd[
{ 2L?jp:$;X
sSiteURL = value; oZVq}}R
} i b$2qy
!Miw.UmPm
]nmVT~lBe"
public String getSFilePath() y$-;6zk\]
{ G!Gbg3:4e5
return sFilePath; +bO]9*g]
} _p<]jt
VSf<(udGr
VAGQR&T?
public void setSFilePath(String value) bm`x;M^M
{ _6O\*|'6
sFilePath = value; |/!3N
} T-.Q
s1"dd7&g'
~6bf-Wg'X
public String getSFileName() I;u1mywd
{ :9c[J$R4
return sFileName; a8Va3Y
} yDl{18~zv
],.1=iY
108cf~2&
public void setSFileName(String value) j2dptM3t{
{ 0<^!<i(%
sFileName = value; r:xbs0 7
} 8l<4OgoK
v%|S)^c?:
}hoyjzv]L
public int getNSplitter() D=>[~u3H
{ o$Jop"To
return nSplitter; y'{*B(
} ;1gWz
()\=(n!J
V{D~e0i/v
public void setNSplitter(int nCount) )0\"8}!
{ ].(l^W
nSplitter = nCount; %k+G-oT5
} /[<1D|f%
} Zb? u'Vm=u
@Q%9b)\\
p#QR^|7"
/* |mS-<e8LY4
**Utility.java Kn#CIFbBN
*/ VnU/_#n
package NetFox; }M0GPpv
1x'H#
+m>)q4e
public class Utility { 9CNeMoA$p:
[t}@>@W|
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public Utility() .@`5>_
{ >;NiG)Z
wRj||yay#-
.Xm?tC<
} # 9@K
4^IqHx;bj
//线程睡眠 -(FhjIr
public static void sleep(int nSecond) 7.W$6U5
{ *U}cj A:ZN
try{ 6Qx[W>I
Thread.sleep(nSecond); =cwdl7N&I
} tupAU$h?!
catch(Exception e) zu!#
{ Sdr,q9+__
e.printStackTrace (); esk~\!d
} v1aE[Q
} G|eJac>
6$5?%ZLJ
//日志 9\S,$A{{*
public static void log(String sMsg) wpK[;
{ /V"6Q'D
System.err.println(sMsg); }J0HEpn4
} z0-[ RGg
9H%dK^C
t^|GcU]
public static void log(int sMsg) ai$s
{ c*DBa]u2
System.err.println(sMsg); 1>'xmp+#
} k8S`44vj
} T/nG\WZbZn
E06)&tF
["~T)d'
/* l\"wdS}
**TestMethod.java }c@duf-l
*/ T%TfkQ__d
package NetFox; iu.$P-s
`s|^
'&<saqA
public class TestMethod { M}\p/r=
ZO*?02c
.:9XpKbt
public TestMethod() 'XP
{ ///xx/weblogic60b2_win.exe \L:+k `
try{ kj]m@mS[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V: P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3( o~|%
SiteFileFetch fileFetch = new SiteFileFetch(bean); XgPZcOzYB
fileFetch.start(); fb_q2p} G
} v&3 Oc
catch(Exception e){e.printStackTrace ();} V[^+lR
Y5R|)x
+T8]R7b9
} /=gU
= 6.i.(L_S
!D~\uW1b
public static void main(String[] args) +BgUnu26
{ +Cs.v.GA5
new TestMethod(); *f k3IvAXu
} &2//\Qz
} dz,4);Mg
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