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)); !9YCuHj!p
} $ (xdF
for(int i=0;i<nEndPos.length-1;i++) 1n&%L8]
{ Sw"h!\c`
nEndPos = nStartPos[i+1]; .I_<\h7
} 5p}j{f
nEndPos[nEndPos.length-1] = nFileLength; _>;MQ)Km~
} $oM>?h_=
} 1L'Q;?&2H,
U9^1A*
@R%qP>_
//启动子线程 IQtQf_"e1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kh=<M{-t
for(int i=0;i<nStartPos.length;i++) p4k}B. f
{ X=abaKl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^,^MW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uM_ww6
nStartPos,nEndPos,i); uKXD(lzX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "M-';;
fileSplitterFetch.start(); U*\K<fw
} l4r>#n\yj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ];6955I!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ai[@2AyU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K$qY^oyQFw
nEndPos = " + nFileLength); Ri_2@U-
// fileSplitterFetch[nPos.length-1].start(); S2Ez}*plp
,.V<rDwN&
.81Y/Gad_
//等待子线程结束 tA< UkPT
//int count = 0; kqj)&0|X
//是否结束while循环 F:P2:s<d-
boolean breakWhile = false; Fp@>(M#3
F7*)u-4Yn
^Mq@} 0
while(!bStop) o@.{|j
{ qWWt5rJ
write_nPos(); cUG^^3!
Utility.sleep(500); F@q9UlfB-
breakWhile = true; 6s~B2t:Y
dm=?o
ercXw7{
for(int i=0;i<nStartPos.length;i++) ,<#Rk'y$
{ ys`oHSf
if(!fileSplitterFetch.bDownOver) BLaNS4e
{ n-jPb064
breakWhile = false; ,vf#e=Z
break; 'm6bfS^T
} zT6nC5E
} C,eP!_O
if(breakWhile) nr -< mQ
break; !DSm[Z1
82EvlmD
DQxuV1
//count++; 1Hr1Ir<KR
//if(count>4) 7rRI-wZ
// siteStop(); i\/'w]
} 1_f+! ns#
NNqvjM-
k,=<G,
System.err.println("文件下载结束！"); ]N'%l]_$
} _Y&.Nw
catch(Exception e){e.printStackTrace ();} 6=$<R4B
} ]jVE
OOXSJE1
2P8wvNDG
//获得文件长度 w5PscEc
public long getFileSize() oNPvksdC;
{ P)f8lU^z
int nFileLength = -1; Ot\[Ya''
try{ Y ?n4#J<
URL url = new URL(siteInfoBean.getSSiteURL()); Q"{Dijc%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .(cpYKFX
httpConnection.setRequestProperty("User-Agent","NetFox"); &}P#<"Fo8Q
=d ;#Nu-
PpG;5
int responseCode=httpConnection.getResponseCode(); |36%B7H
if(responseCode>=400) d;gs1]E50
{ gU|:Y&lFZg
processErrorCode(responseCode); #CI0G
return -2; //-2 represent access is error \rxjvV4fcZ
} FA{Q6fi:2
:X'B K4EN
9^n0<(99b
String sHeader; ]*k ~jY,
.4"BN<9
I9+h-t
for(int i=1;;i++) 80Fa i
{ \yw5`5g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \C>IVz<O
//Utility.log(in.readLine()); ;K8}Yq9p9
sHeader=httpConnection.getHeaderFieldKey(i); rm3/R<
if(sHeader!=null) {X?1}5ry
{ !<~.>5UQ
if(sHeader.equals("Content-Length")) + <E zv
{ weu+$Kr
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +8?18@obp
break; _p1!8*0]
} -['& aey}a
} WZ,k][~
else Un)Xe
break; Yq|_6zbYf
} ;-py h(
} hO.b?>3NL
catch(IOException e){e.printStackTrace ();} Fy E#@ R
catch(Exception e){e.printStackTrace ();} e/+.^ '{
GU/P%c/V
+3zQ"lLD^
Utility.log(nFileLength); [DeDU:
N]iarYc
Q) aZ0 Pt
return nFileLength; B%Qo6*b
} EU:N9oT
]WYub1
>/4[OPB0R
//保存下载信息（文件指针位置） #V/{DPz
private void write_nPos() 5ta;CG
{ 0F- +)S?M[
try{ Uq'W<.v5
output = new DataOutputStream(new FileOutputStream(tmpFile)); S{e3aqT#N
output.writeInt(nStartPos.length); 9<3}zwJ
for(int i=0;i<nStartPos.length;i++) sj/k';#g
{ JSju4TQ4
// output.writeLong(nPos); ._]Pz6
output.writeLong(fileSplitterFetch.nStartPos); qvy*; <w
output.writeLong(fileSplitterFetch.nEndPos); RiR],Sj
} x!s=Nola
output.close(); K7JZUS`C!
} iVeH\a
catch(IOException e){e.printStackTrace ();} P~!,"rY
catch(Exception e){e.printStackTrace ();} MLTS<pW/
} gS[B;+d
;g#nGs>
7w9'xY
//读取保存的下载信息（文件指针位置） tx<^PV2
private void read_nPos() !'# D~
{ @UdF6:T
try{ d\3 %5Y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5p~5-_JX
int nCount = input.readInt(); jf;n*
nStartPos = new long[nCount]; )XSHKPTQ1
nEndPos = new long[nCount]; kGnT4R*E
for(int i=0;i<nStartPos.length;i++) 1CZO+MB&"$
{ d42Y`Wu
nStartPos = input.readLong(); \/ri|fm6l#
nEndPos = input.readLong(); +\ "NPK@3
} .7Yox1,
input.close(); @.k^ 8hc
} 9\Ff z&
catch(IOException e){e.printStackTrace ();} V73/q
catch(Exception e){e.printStackTrace ();} PeiRe
} *mj=kJ7(
5-fASN.Lx
ipGxi[Vav
private void processErrorCode(int nErrorCode) (?(gz#-
{ ZZHQ?p-
System.err.println("Error Code : " + nErrorCode); v\G7V
} `q^qe>'
R%2.N!8v
7uw-1F5x7
//停止文件下载 [ t8]'RI%
public void siteStop() vmNI$KZM
{ b5%<},ySq
bStop = true; l0t(t*[Mj
for(int i=0;i<nStartPos.length;i++) l*wGKg"x3
fileSplitterFetch.splitterStop(); I<<1mEk
*K?UWi#$
L;?h)8
} E+<GsN]
} M/[_~
//负责部分文件的抓取 ~AaEa,LQ
**FileSplitterFetch.java ?ZC!E0]
*/ Ug0c0z!b
package NetFox; ,{(XT7hr
V,& OO
e#}Fm;|d
import java.io.*; Qp:m=f6@
import java.net.*; / s Apj
rrgOp5aV"
^%Y-~yB-
public class FileSplitterFetch extends Thread { ps`j>vX*
t&x\@p9
3jW&S
String sURL; //File URL G"(aoy, co
long nStartPos; //File Snippet Start Position W<^t2j'
long nEndPos; //File Snippet End Position *6u2c%^
int nThreadID; //Thread's ID YE*|KL^
boolean bDownOver = false; //Downing is over K7{B!kX4k
boolean bStop = false; //Stop identical pQ^V<6z}
FileAccessI fileAccessI = null; //File Access interface ct,;V/Dx
F}[!OYyg
i-wWbZ-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x_-V{ k
{ T)q Uf H
this.sURL = sURL; mb3aUFxA;
this.nStartPos = nStart; 2PeMt^
this.nEndPos = nEnd; tG9C(D`G
nThreadID = id; &F7_0iAP(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BL>~~
} d+]=l+&
0cfGI%
@U?&1.\
public void run() s%vy^x29
{ qW4\t
while(nStartPos < nEndPos && !bStop) "D4% A!i
{ (s|WmSQ
x7gd6"10^
(w"(RM~
try{ %}~(%@qB>+
URL url = new URL(sURL); |9FrVO$M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?A.ah
httpConnection.setRequestProperty("User-Agent","NetFox"); %c]N-
String sProperty = "bytes="+nStartPos+"-"; Dz2Z (EXI~
httpConnection.setRequestProperty("RANGE",sProperty); }Cfl|t<5f
Utility.log(sProperty); |-*50j l
S{MB$JA
U%BtBPL
InputStream input = httpConnection.getInputStream(); E|RC|Sz=u
//logResponseHead(httpConnection); ?0sTx6x@
GCr]x '
ld|GY>rH
byte[] b = new byte[1024]; 6'uCwAQU
int nRead; X$Q.A^9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b-<@3N.9]
{ 726UO#*
nStartPos += fileAccessI.write(b,0,nRead); Tz9 (</y
//if(nThreadID == 1) hc0$mit
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #E\6:UnT
} %8Y+Df;ax
5{DwD{Q
69:-c@L0
Utility.log("Thread " + nThreadID + " is over!"); o F_{oV'
bDownOver = true; Y1ca=ewFx
//nPos = fileAccessI.write (b,0,nRead); jxhZOLG
} x11riK
catch(Exception e){e.printStackTrace ();} j5/|1N
} `0_ Y| 4KB
} G[_Z|Xi1
OfA+|xT&
x\:KfYr4Y;
//打印回应的头信息 br k*;
public void logResponseHead(HttpURLConnection con) +`mI\+y,
{ <rui\/4NJ
for(int i=1;;i++) :w|=o9J
{ G^VOA4
String header=con.getHeaderFieldKey(i); bF,.6iKI
if(header!=null) F9las#\J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8gt*`]I
Utility.log(header+" : "+con.getHeaderField(header)); Bzt:9hr6BO
else qJonzFp7
break; {+{p.
} }F9#3W&`c
} Q9f5}
$txF|Fj]^A
uz$p'Q
public void splitterStop() {wz_ngQ
{ EDnZ/)6Gg
bStop = true; p__N6a
} F)imeu
{ JDD"z
H;tE=
} \K%M.>]vq
AkO);4A;Jd
:Zob"*T
/* [Ne'2z
**FileAccess.java ]Z=al`-
*//文件访问(定位，写) X$P(8'[9A
package NetFox; suLC7x`Z
import java.io.*; FQ47j)p;
?0JNaf
[^/a`Kda8
public class FileAccessI implements Serializable{ 2_M+o]Z^
}o[<1+W(.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q j9q
RandomAccessFile oSavedFile; {t|#>UCK
long nPos; &^ s8V]^
>mEfd=p
@8A[HP
public FileAccessI() throws IOException }'>mT,ytgk
{ *W,[k&;:
this("",0); Hmx.BBz
} TVSCjI
a+~b3
k:@N6K/$P^
public FileAccessI(String sName,long nPos) throws IOException alNn(0MG
{ %Kp^wf#o9
oSavedFile = new RandomAccessFile(sName,"rw"); :kwDa a
this.nPos = nPos; E GZiWBr
oSavedFile.seek(nPos); 1:@ScHS
} $T7 qd
Nvh&=%{g
>w.%KVBJ
public synchronized int write(byte[] b,int nStart,int nLen) Z6Kp-z(l3
{ @B(E&
int n = -1; zh\"sxL
try{ 9v3n4=gc
oSavedFile.write(b,nStart,nLen); t6\--lk_
n = nLen; #mK?:O\-1
} Gui[/iY,F
catch(IOException e) uf (_<~
{ hJk:&!M=T
e.printStackTrace (); q0vZR"y
} X*5N&AJ
UVgSO|Tg
\l 8_aj
return n; `Gl[e4U
} ?gvu E1
E_Y!in 70
Bm%|WQK
} O2="'w'kR
~kDJ-V
D+~*nc~ g
/* e5 zi"~
**SiteInfoBean.java )vVf- zU
*/ WQD:~*C:
package NetFox; 'Yc^9;C(
hH%fWB2(
+qT+iHa|n
public class SiteInfoBean { m@w469&<(q
RQ^ \|+_
W@'*G*f
private String sSiteURL; //Site's URL b^ [ z'
private String sFilePath; //Saved File's Path mh SknyqT
private String sFileName; //Saved File's Name 1~LfR
private int nSplitter; //Count of Splited Downloading File hk S:_e=
UTN[!0[
.P?n<n#
public SiteInfoBean() 2Yd@V}
{//nSplitter的缺省值为5 [cl+AV "
//default value of nSplitter is 5 2cRru]VZ5
this("","","",5); IXm[c@5l
} $% gz,{
.n)R@&9
ue'dI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I'p+9H$
{ }4h0{H
sSiteURL= sURL; :2C <;o
sFilePath = sPath; >Q[ Z{
sFileName = sName; SB.=x
this.nSplitter = nSpiltter; }Ya! [tX
0) F\aJ4Y
Y"yrc0'&T
} IA]wO%c
3Lq9pdM>2@
ux| QGT2LY
public String getSSiteURL() G#6Z@|kVw
{ KT>Y^
return sSiteURL; ?d{O'&|:
} #5'@at'1
hdSP#Y'-
qfxEo76'
public void setSSiteURL(String value) L%QRWhB
{ &?Q^i">cZ
sSiteURL = value; 6 v~nEw
} zDbO~.d
aIrM-c8.O
b0f6p>~q^
public String getSFilePath() C8|#
{ :eJJL,v
return sFilePath; [/VpvQ'
} X-,oL.:c
@7.7+blS"H
~kSOYvK$'
public void setSFilePath(String value) t*A[v
{ UX<-jY#'V
sFilePath = value; NJ-Ji> w
} J2! Q09 }5
iXL^[/}&?M
U?5lqq
public String getSFileName() dga4|7-MY
{ BGwD{6`U
return sFileName; l"DHG`kb
} ,R3TFVV!?
m.! M#x2!
Di4GaKa/
public void setSFileName(String value) >w,jaQ
{ M+HhTW;I=
sFileName = value; =l${p*ABQ
} yG7H>LF?8
^~7Mv^A
:l1-s]
public int getNSplitter() g0}jE%)
{ {x_cgsn
return nSplitter; ',t*:GBZCf
} ZZTf/s*
]FIIs58IM
~K<h~TNP
public void setNSplitter(int nCount) ,r]H+vWS
{ -38"S;M8
nSplitter = nCount; o^*:
} pL`Q+}c}
} -;&I S
ZX1/6|_
"Y&
/* /~f[>#
**Utility.java lBs-u h
*/ ABkDOG2br
package NetFox; RjPkH$u'Pj
F'|e:h
r `n|fD.
public class Utility { {#4a}:3
H>;,r,
G kG#+C0L
public Utility() [6JDS;MIN
{ 7 @}`1>97
q9j~|GE|
Dykh|"
} D M+MBK
I9>vm]
//线程睡眠 &0%Zb~ts
public static void sleep(int nSecond) F --b,,
{ SG|AJ9
try{ \ERxr
Thread.sleep(nSecond); F8{gJaP x
} ]sL.+.P
catch(Exception e) Y;huTZ
{ t!6uz
e.printStackTrace (); a=A12<
} pI8z.JD
} ]Sa#g&}T>
8]`s&d@GY
//日志 GIcq|Pe
public static void log(String sMsg) zuW4gJ
{ HR8YPU5
System.err.println(sMsg); X';qcn_^
} V6HZvuXV!
,Ww}xmq1H
<PuY"-`/Oc
public static void log(int sMsg) Q<;EQb#
{ Zy;jp*Q
System.err.println(sMsg); F+Qnf'at1
} e7{6<[k3+$
} 3C%|src
|9]-_a
qK#"uU8B
/* zF[Xem
**TestMethod.java )xa)$u
*/ $hcv}<$/
package NetFox; @<pd@Mpf]
R8u8jG(4
aY(s &
public class TestMethod { ]?D$n
SM RKEPwp&
)D6i {I0
public TestMethod() V*Fy@
{ ///xx/weblogic60b2_win.exe 5YNAb/!!F
try{ "N=$=Dy>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]wEI*c(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C=q&S6/+
SiteFileFetch fileFetch = new SiteFileFetch(bean); h'=)dFw7
fileFetch.start(); { >izfG,\
} g_P98_2f.k
catch(Exception e){e.printStackTrace ();} y'odn;
mhhc}dS(H
8~-TN1H
} |^UQVNJ
)^s>21
;7?oJH;
public static void main(String[] args) H,w8+vZ4\
{ z[QDJMt>
new TestMethod(); &ZC{ _t
} 1R~$m
} 6O6B8
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