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)); T;5r{{
} )%d*3\Tsd
for(int i=0;i<nEndPos.length-1;i++) ntVS:F
{ vBcq_sbo
nEndPos = nStartPos[i+1]; Pe;Y1Qq>>
} eE GfM0
nEndPos[nEndPos.length-1] = nFileLength; vy9 w$ls
} jszK7$]^
} [ic870_
O@V%Cu
r!PpUwod
//启动子线程 Z?5V4F:f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =O).Lx2J
for(int i=0;i<nStartPos.length;i++) "A$!, PX6
{ `Ag{)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), **3 z;58i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9iUrnG*
nStartPos,nEndPos,i); q 11IkDa
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p Z: F:
fileSplitterFetch.start(); TS2ZF{m
} Uu 8,@W+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #Lv2Zoi>G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4db(<h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *z*uEcitW
nEndPos = " + nFileLength); c2t=_aAIPQ
// fileSplitterFetch[nPos.length-1].start(); j>-gO,v, y
4%nE*H%
F8:vDv
//等待子线程结束 Zwz&rIQpT
//int count = 0; ",7Q
//是否结束while循环 C?Bl{4-P}*
boolean breakWhile = false; #|&Sc_#4)
!$-\;<bZw
YG[;"QR
while(!bStop) #9-P%%kQ
{ U4aU}1RKz
write_nPos(); /='. 4v
Utility.sleep(500); ]vWKR."4
breakWhile = true; VXIP0p@
z|EEVNFd&
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for(int i=0;i<nStartPos.length;i++) $6OkIP.
{ WmY``
if(!fileSplitterFetch.bDownOver) VCXJwVb
{ }by;F9&B
breakWhile = false; S}p4iE"n
break; .ZvM^GJb
} ![]``g2
} i;LXu%3\
if(breakWhile) z9FfU
break; 35E_W>n
:8CvRO*<
1$M@]7e+!+
//count++; wr[,
//if(count>4) \b%kf99
// siteStop(); ^6_e=jIN
} UfN&v >8f
h4q|lA6!k8
z!l.:F
System.err.println("文件下载结束！"); .pvi!NnL-
} &?mD$Eo
catch(Exception e){e.printStackTrace ();} Tyvtmx M
} ?c[*:N(
o.0ci+z@
QUu}Xg:
//获得文件长度 G:~k.1y[
public long getFileSize() nqInb:
{ GGnpjwXeH
int nFileLength = -1; \"X!2
try{ tjupJ*Rt
URL url = new URL(siteInfoBean.getSSiteURL()); C:PMewn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O3I8k\`
httpConnection.setRequestProperty("User-Agent","NetFox"); :<}=e@/~|
n4}Br;%
?b(=1S\E'^
int responseCode=httpConnection.getResponseCode(); ?VP8ycm
if(responseCode>=400) "jG}B.l=,
{ G6T_O
processErrorCode(responseCode); xuqv6b.
return -2; //-2 represent access is error a)wJT`xu
} ,%uo6%
{zMU#=EC
"?V0$-DR
String sHeader; |&RU/a
&YF^j2
1v71rf&w
for(int i=1;;i++) "rx-_uK*
{ O^oWG&Y;v
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vQ;Ex
//Utility.log(in.readLine()); O8h%3&
sHeader=httpConnection.getHeaderFieldKey(i); V5UF3'3;}
if(sHeader!=null) ["h5!vj
{ 9I&xfvD,
if(sHeader.equals("Content-Length")) nih0t^m'
{ i\,-oO
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7Zlw^'q$:L
break; M7pOLP_1jB
} B}lvr-c#
} u6AA4(
else 5`~PR :dN
break; x[a<mk
} vN`klDJgW[
} ibj87K
catch(IOException e){e.printStackTrace ();} vX/T3WV
catch(Exception e){e.printStackTrace ();} C uB`CI
!@}wDt
I}1NB3>^
Utility.log(nFileLength); wOU_*uY@6'
kM,C3x{A
9[<)WQe6M
return nFileLength; RW<D<5C
} <g"{Wv: h
Y$"O VC
%5(I/zB
//保存下载信息（文件指针位置） jYk&/@`Ly
private void write_nPos() Dfmjw
{ hb}+A=A=+
try{ ynthDEo
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;lE%M
output.writeInt(nStartPos.length); E|iQc8gr&
for(int i=0;i<nStartPos.length;i++) F(>Np2oi6
{ .+$Q<L
// output.writeLong(nPos); <3LbNFP
output.writeLong(fileSplitterFetch.nStartPos); YtmrRDQs
output.writeLong(fileSplitterFetch.nEndPos); GPN]9
} e|"WQ>
output.close(); Y3Yz)T}UkS
} yDzc<p\`
catch(IOException e){e.printStackTrace ();} LRL,m_gt
catch(Exception e){e.printStackTrace ();} VK m&iidU
} '=b/6@&
{*G9|#[/@
].-1v5
//读取保存的下载信息（文件指针位置） h`^jyoF"(
private void read_nPos() dYJ(!V&
{ y [}.yyye
try{ 0XE4<U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eA2@Nkw~)
int nCount = input.readInt(); %)1y AdG 8
nStartPos = new long[nCount]; rC5 p-B%
nEndPos = new long[nCount]; ,E S0NA
for(int i=0;i<nStartPos.length;i++) C5o#i*|
{ Cd#(X@n
nStartPos = input.readLong(); Bs^aII$
nEndPos = input.readLong(); *4\:8
} ua3~iQj-
input.close(); !fE`4<|?
} "\:`/k3
catch(IOException e){e.printStackTrace ();} +r2+X:#~T
catch(Exception e){e.printStackTrace ();} ]d$8f
} "@V Y
j()7_
hOjk3 k
private void processErrorCode(int nErrorCode) oB(?_No7
{ ,Vc6Gwm
System.err.println("Error Code : " + nErrorCode); _kef0K6
} ]L5@,E4.
=^M/{51j
L/$H"YOv
//停止文件下载 glO^yZs
public void siteStop() Ag-(5:
{ , qMzWa
bStop = true; XO.jl"xu
for(int i=0;i<nStartPos.length;i++) slCx w$
fileSplitterFetch.splitterStop(); }Y12
n(1l}TJy
@LF,O}[2J
} R0KPZv-
} .s?L^Z^
//负责部分文件的抓取 PxvyN_B#>
**FileSplitterFetch.java P)Jgs
*/ ]C!gQq2'a
package NetFox; u-QB.iQ+s
ha]VWt%}
]E5o1eeg
import java.io.*; WlOmJtt4)
import java.net.*; BtkOnbz8X
Ri<u/ ]oR"
)1?y 8_B
public class FileSplitterFetch extends Thread { 3Z>Ux3[
r8`ffH
|mZxfI
String sURL; //File URL Ytn9B}%o
long nStartPos; //File Snippet Start Position xG~P+n7t5$
long nEndPos; //File Snippet End Position ER%^!xA
int nThreadID; //Thread's ID [_BP)e
boolean bDownOver = false; //Downing is over d[iQ`YW5
boolean bStop = false; //Stop identical bV^rsJm
FileAccessI fileAccessI = null; //File Access interface x]}^v#
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uy>q7C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException lU8l}Ndz"
{ T$8)u'-pa
this.sURL = sURL; (~p< P+
this.nStartPos = nStart; ; 5*&xz
this.nEndPos = nEnd; )3cAQ'w
nThreadID = id; j\eI0b @*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ">\?&0
} 'g}!
<$D`Z-6
=*oJEy"
public void run() N=V==Dbu-
{ 2=*H 8'k
while(nStartPos < nEndPos && !bStop) OAgniLv
{ 9SX +
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ahusta
try{ y6g&Y.:o
URL url = new URL(sURL); >xN .F/[K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A7%)~z<
httpConnection.setRequestProperty("User-Agent","NetFox"); NDN7[7E
String sProperty = "bytes="+nStartPos+"-"; nGC/R&
httpConnection.setRequestProperty("RANGE",sProperty); &h}#HS>l
Utility.log(sProperty); %Hu5K>ZNYp
VF+KR*
Sj3+l7S?
InputStream input = httpConnection.getInputStream(); p?02C#p
//logResponseHead(httpConnection); l[dK[4
wo3d#=
eb?x9h
byte[] b = new byte[1024]; &sl0W-;0
int nRead; w2?3wrP3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >R'F,
{ ?e%ZOI
nStartPos += fileAccessI.write(b,0,nRead); lt/1f{v[:
//if(nThreadID == 1) 1y:-N6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]}V<*f
} 0j^Kgx
B`EJb71^Xy
9=s<Ld
Utility.log("Thread " + nThreadID + " is over!"); ko!)s
bDownOver = true; R!HXhQ
//nPos = fileAccessI.write (b,0,nRead); W~)}xy
} 21n?=[
catch(Exception e){e.printStackTrace ();} v_yw@
} t$`r4Lb9/
} `~cqAs}6]Q
F/]2G^-
\__i
//打印回应的头信息 aEB_#1
public void logResponseHead(HttpURLConnection con) <;lkUU(WT2
{ b]e"1Y)D-
for(int i=1;;i++) A@`}c,G
{ L7l FtX+b
String header=con.getHeaderFieldKey(i); =0 #OU
if(header!=null) 11NQR[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9p]QM)M
Utility.log(header+" : "+con.getHeaderField(header)); wH*-(*N"
else 7 W5@TWM
break; jVi) Efy
} td$E/h=3
} IYv`IS"
x5pdS:
_T60;ZI+^
public void splitterStop() 'B|JAi?
{ 6%'QjwM_
bStop = true; MxKS4k
} /l3V3B7
GblA9F7
Y/F6\oh
} 8|gIhpO?^
[+Iz@0q
Zpt\p7WQ
/* *VCXihgo
**FileAccess.java $t+,Tav
*//文件访问(定位，写) Dm981t>wL
package NetFox; 10Q ]67
import java.io.*; !aUs>1i
i$Ul(?
-OV&Md:~
public class FileAccessI implements Serializable{ yxPazz
2Ah#<k-gC;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {p2!|A&a
RandomAccessFile oSavedFile; hE{K=Tz$
long nPos; A`%k:@
U gat1Pz
g&L!1<, p
public FileAccessI() throws IOException 70?\ugxA
{ Z-%\ <zT
this("",0); ic:zsuEm
} b`Zx!^
M/f<A$xx_
#~]zhHI
public FileAccessI(String sName,long nPos) throws IOException 'ms-*c&
{ }rUN_.n4z
oSavedFile = new RandomAccessFile(sName,"rw"); |"}FXaO
this.nPos = nPos; "S[450%
oSavedFile.seek(nPos); (MM]N=Tw4
} yZY\MB/
qz_7%c]K[
iQ67l\{R
public synchronized int write(byte[] b,int nStart,int nLen) )MVz$h{c.]
{ Pm6pv;WK
int n = -1; K-)] 1BG
try{ (XTG8W sN
oSavedFile.write(b,nStart,nLen); ;fTKfa
n = nLen; HQdxL*N%^
} FjHv
catch(IOException e) z_$%-6
{ BKCiIfkZ
e.printStackTrace (); 5Pc;5 o0C
} au(D66VO
r8?gD&c}
8 /]S^'>
return n; :LQYo'@yB
} g/d<Zfq<{
P= BZ+6DS
EU 6oQ
} KAJi
2QcOR4_V
&J]K3w1p
/* Pbn*_/H
**SiteInfoBean.java 1s&zMWC
*/ WDYeOtc
package NetFox; tKuwpT1Qc
"S]0
X,% 0/6*]
public class SiteInfoBean { 4"(Bu/24
EWhK0Vej=
9rX&uP)j^#
private String sSiteURL; //Site's URL $99n&t$Y
private String sFilePath; //Saved File's Path oCv.Ln1;Z
private String sFileName; //Saved File's Name NR6#g,+7
private int nSplitter; //Count of Splited Downloading File Wis~$"
3pROf#M
n38p!oS
public SiteInfoBean() ub0.J#j@
{//nSplitter的缺省值为5 Z clQ
//default value of nSplitter is 5 <$$yw=ef
this("","","",5); H2 {+)
} u~:y\/Y6
x_}:D *aI
Mj3A5;#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h2A <"w
{ qA7>vi%
sSiteURL= sURL; k"%~"9
sFilePath = sPath; K7B/s9/xs
sFileName = sName; |Zpfq63W
this.nSplitter = nSpiltter; *;slV3
+o{R _
M/'sl;
} [S%_In
?3,:-"(@p
.VJMz4$]O
public String getSSiteURL() CsR$c,8X.
{ 1=c\Rr9]
return sSiteURL; &{hL&BLr
} L#{S!P,"
re?,Wext\
IPKbMlV#d
public void setSSiteURL(String value) f*% D$Mqg
{ SM#]H-3
sSiteURL = value; i>A s;*
} I*{nP)^9
g)[V(yWu
*%NT~C q
public String getSFilePath() /t57!&
{ ~H_/zK6e
return sFilePath; nNV'O(x}
} =:Fc;n>c<K
Fnv;^}\z
}eU*( }<^
public void setSFilePath(String value) ~ 'cmSiz-
{ xh,qNnGGi
sFilePath = value; \ a<h/4#|
} k,6f &#x
%@aSe2B
"Yv_B3p
public String getSFileName() .V/Rfq
{ ::lKL
return sFileName; wu!59pL
} 33x{CY15
bHYy}weZ
X/!o\yyT
public void setSFileName(String value) 6 7.+ .2
{ [Td4K.c
sFileName = value; `pa!~|p
} {hjhL: pg
%D34/=(X
{SPq$B_VR
public int getNSplitter() Oc#syfO
{ tjGn|+|k
return nSplitter; l"T44CL;
} ]=I@1B;_m
+F` S>U
qvsd5PeCO
public void setNSplitter(int nCount) W]1)zO
{ . B9iLI
nSplitter = nCount; LVfF[
} DB|Y
} &K.d'$q
]L $\ #
3?9IJ5p
/* YeL#jtC
**Utility.java "@@u3`#
*/ &< `NT D
package NetFox; ?0?#U0(;u
QB uMJm
Ad8n<zt|
public class Utility { wLH>:yKUU
&*,#5.
HxV=F66"
public Utility() =E4LRKn
{ "Mn6U-
H>IMf/%5N-
ay ;S4c/_
} u@UMP@"#
=,=A,kI[;
//线程睡眠 /GN<\_o=q
public static void sleep(int nSecond) SI-qC
{ )e+>w=t
try{ ^z IW+:
Thread.sleep(nSecond); F=e8IUr
} 2!m/
catch(Exception e) IGQaDFr
{ 4#xDgxg\f
e.printStackTrace (); T|eu
} 9igiZmM
} Q800y??&J
nu[ML
//日志 M*, -zGr
public static void log(String sMsg) !qh]6%l
{ ,{u yG:
System.err.println(sMsg); <I\/n<*
} Uw. `7b>B
wPd3F.<$
QUc= &5 %
public static void log(int sMsg) ^R7lom.
{ rdP[<Y9
System.err.println(sMsg); 4{U T!WIi
} ?%-DfCS
} Eqd<MY7
wedbx00o
wr/"yQA]
/* qZtzO2Mt
**TestMethod.java !mJ"gg
*/ v!6 c0a
package NetFox; P6-s0]-g
DS(}<HK{
l'-Bu(
public class TestMethod { s4y73-J^.v
%~H-)_d20
?}tFN_X"
public TestMethod() kWMl
{ ///xx/weblogic60b2_win.exe p Z|V 3
try{ x_N'TjS^{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (l~AV9!m:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !*dI|k
SiteFileFetch fileFetch = new SiteFileFetch(bean); (&F}/s gbi
fileFetch.start(); XH4
} %+W{iu[|
catch(Exception e){e.printStackTrace ();} r1`x=r
|P HT694Uz
f;o5=)Y
} eCU:Q
"Y =;.:qe
.PIL +x*]N
public static void main(String[] args) BDW^7[n
{ X8a/ `Y,
new TestMethod(); s^G.]%iU
} A@!qv#'
} 45@ I*`
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