http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); AYHB?xOpR
} $Z(fPKRN/
for(int i=0;i<nEndPos.length-1;i++) 6rP[*0[
{ SHS:>V
nEndPos = nStartPos[i+1]; =(b;Cow
} ^l;nBD#nJ
nEndPos[nEndPos.length-1] = nFileLength; w-\U;&8
} YJ_`[LnL
} t_5b
=A&x d"
FLdO
//启动子线程 68?oV)fE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h"/FqO
for(int i=0;i<nStartPos.length;i++) 0o2o]{rM{2
{ i|+ EC_^<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g=.~_&O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (lF;c<69
nStartPos,nEndPos,i); x;"!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *F/uAI^)
fileSplitterFetch.start(); -]c5**O}
} Z#YkAQHv5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `"QUA G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); QxCZ<|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /l_$1<c
nEndPos = " + nFileLength); ""l_&3oz
// fileSplitterFetch[nPos.length-1].start(); d (]t}
i>6SY83B}
?P4@U9i
//等待子线程结束 <SI&e/
//int count = 0; 6#VG,'e3
//是否结束while循环 x'*,~u
boolean breakWhile = false; <cG .V|B
9frP`4<)
33x3zEUt6
while(!bStop) % INRds
{ K1#Y{k5D}
write_nPos(); yZ3/Ia>,
Utility.sleep(500); =$601r
breakWhile = true; iK{q_f\"
Ry*NRP;
CBdSgHA3>
for(int i=0;i<nStartPos.length;i++) ^c{}G<U^
{ 3U=q3{%1
if(!fileSplitterFetch.bDownOver) ,?i^i#Wqzg
{ dgPJte%i
breakWhile = false; e'aKI]>a
break; "6rZn_H/|
} 8[5%l7's
} ,}F2l|x_
if(breakWhile) *FDz20S
break; !J!zi
i.2O~30ST
h-hU=I8
//count++; hKjvD.6]%
//if(count>4) pHFlO!#]|
// siteStop(); , RfU1R
} -H~g+i*J
~J!a?]
H4 Y7p
System.err.println("文件下载结束！"); g6EdCG.V
} 0$l=ME(
catch(Exception e){e.printStackTrace ();} Malt7M
} nMc3.fM
9oS\{[x.
bT-(lIU
//获得文件长度 f|Kd{ $VO
public long getFileSize() R[ S*ON
{ (FZL>
int nFileLength = -1; ,$5;
try{ #G{}Rd|!
URL url = new URL(siteInfoBean.getSSiteURL()); =]oBBokV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uoFH{.)
httpConnection.setRequestProperty("User-Agent","NetFox"); l)D18
FOpOS?Cr'
h*)spwF-
int responseCode=httpConnection.getResponseCode(); T3Kq1 Rh
if(responseCode>=400) ,HS\(Z
{ Q6Q>b4 .3
processErrorCode(responseCode); "[@-p
return -2; //-2 represent access is error Cca( oV
} $=iz&{9
<oV _EZ
m}6GVQ'Q
String sHeader; ~$#DB@b
:BCjt@K}
N-jFA8n
for(int i=1;;i++) !Qrlb>1z-
{ }txHuq1Q.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .rSeJZzuj
//Utility.log(in.readLine()); ;3Fgy8T
sHeader=httpConnection.getHeaderFieldKey(i); h+zJ"\
if(sHeader!=null) J5k\R+\H
{ 5ejdf
if(sHeader.equals("Content-Length")) *gHOH!K,S
{ )=9\6zXS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X55Eemg/
break; 2|tZ xlt-
} /4RKA!W
} =Xm [
else LYGFEjS[
break; TuwH?{ FzK
} w|>:mQnU
} 1 dz&J\|E#
catch(IOException e){e.printStackTrace ();} t?28s/?
catch(Exception e){e.printStackTrace ();} }CaL:kY8
O-wR48Q
)<DL'
Utility.log(nFileLength); =Z2U
6 )0$UW
#g4X`AHB
return nFileLength; xex/L%!Rj
} 6;dB
J\_tigd
"FcA:7+
//保存下载信息（文件指针位置） #1z}~1-
private void write_nPos() "6 dC
{ |=l;UqB
try{ A[XEbfDO
output = new DataOutputStream(new FileOutputStream(tmpFile)); Il'+^u_ <
output.writeInt(nStartPos.length); |g> K$m^
for(int i=0;i<nStartPos.length;i++) `iv,aQ '
{ ],>Z'W
// output.writeLong(nPos); )eY3[>`
output.writeLong(fileSplitterFetch.nStartPos); Eo)Q> AM
output.writeLong(fileSplitterFetch.nEndPos); J.?6a:#bU/
} b,D+1'
output.close(); SR%h=`t
} /V46:`V
catch(IOException e){e.printStackTrace ();} s4;SA
catch(Exception e){e.printStackTrace ();} rxIfatp^
} H~J#!3
h<6@&yzp
oVb6,Pn
//读取保存的下载信息（文件指针位置） ]^VC@$\)+
private void read_nPos() Jmf&&)p
{ 6~&4>2b0f
try{ +aEE(u6%E@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pUYa1=
int nCount = input.readInt(); q,^^c1f
nStartPos = new long[nCount]; &0K H00l
nEndPos = new long[nCount]; o9<jj>R;
for(int i=0;i<nStartPos.length;i++) H;G*tje/M
{ j*q]-$2E
nStartPos = input.readLong(); ;?yd;GOt)
nEndPos = input.readLong(); OY51~#BF
} lk%rE
input.close(); qdL;Ii<Y0
} .AWRe1?
catch(IOException e){e.printStackTrace ();} B<H5WI
catch(Exception e){e.printStackTrace ();} U"aFi
} x>!#8?-h
(JL{X`gs#
xx#;)]WT
private void processErrorCode(int nErrorCode) +g/y)]AP
{ PE]jYyyHtU
System.err.println("Error Code : " + nErrorCode); Jf|J":S
} 0{@E=}}h
^$6EO)<
<lB^>Hfu
//停止文件下载 H--(zxK
public void siteStop() c9=;:E
{ ]p `#KVW
bStop = true; W.HM!HQp
for(int i=0;i<nStartPos.length;i++) U9y[b82
fileSplitterFetch.splitterStop(); mPi4.p)
>(|T]u](q
J3oH^
} aHXd1\6m
} p4fU/
//负责部分文件的抓取 (VI4kRj
**FileSplitterFetch.java {3i.U028]
*/ 0AZ Vc
package NetFox; Pn[-{nz
@v2_gjRe
y['$^T?oP
import java.io.*; {uM*.]
import java.net.*; <KoiZ{V
-L NJ*?b
Ev,>_1#Xm
public class FileSplitterFetch extends Thread { ^r?ZrbSbz
lSPQXu*[
2>Xgo%
String sURL; //File URL ]t=m
long nStartPos; //File Snippet Start Position D8m1:kU
long nEndPos; //File Snippet End Position 9G[!"eZ}
int nThreadID; //Thread's ID $>hPB[[
boolean bDownOver = false; //Downing is over 7.,C'^ci
boolean bStop = false; //Stop identical _s[ohMlh
FileAccessI fileAccessI = null; //File Access interface FMc$?mm
CCNrjaA
2`9e20
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bX Q*d_]WT
{ Q( U+o-
this.sURL = sURL; |C301ENZ
this.nStartPos = nStart; bJ4})P&
this.nEndPos = nEnd; _D1Uc|
nThreadID = id; ?NOc]'<(G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M4w,J2_8MK
} tg_xk+x
?1T)cd*
2F%2K?$`Ej
public void run() 0ft81RK
{ 84j6.\,
while(nStartPos < nEndPos && !bStop) vMu6u .e
{ O`j1~o<{
Sg
-+?ZJ^A
try{ uH="l.u
URL url = new URL(sURL); L1ro\H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NOM6},rp
httpConnection.setRequestProperty("User-Agent","NetFox"); w%~UuJ#i
String sProperty = "bytes="+nStartPos+"-"; )lg>'O
httpConnection.setRequestProperty("RANGE",sProperty); UCV1{
Utility.log(sProperty); I!1|);li
kn<IWW_t
PgIH(
InputStream input = httpConnection.getInputStream(); ywQ[>itMa
//logResponseHead(httpConnection); o1lhVM`15
W5cBT?V
RT`.S uN
byte[] b = new byte[1024]; 1i3;P/
int nRead; VJbsM1y M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #djby}hi
{ qJ(XW N H
nStartPos += fileAccessI.write(b,0,nRead); u+EZ"p;o
//if(nThreadID == 1) =d`w~iC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )hG4,0hv&
} Hq$&rNnq\
wtM1gYl^
8]h~jNku
Utility.log("Thread " + nThreadID + " is over!"); O]_a$U*6
bDownOver = true; "`Q&s
//nPos = fileAccessI.write (b,0,nRead); W_.WMbT
} 4j|IG/m
catch(Exception e){e.printStackTrace ();} E<RPMd @a
} UahsX
} ;n,xu0/
(vP<}
gcF:/@:Rm
//打印回应的头信息 z@I'Ryalyc
public void logResponseHead(HttpURLConnection con) sGFvSW
{ Zzn N"Si,
for(int i=1;;i++) :A7\eN5
{ =xw+cs1,x
String header=con.getHeaderFieldKey(i); y>^FKN/
if(header!=null) w)N~u%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ; DXsPpZC
Utility.log(header+" : "+con.getHeaderField(header)); -wa"&Q
else R_W6}
break; ~+ kfb^<-
} <@Z`<T6
} JR_%v=n~x
UpaF>,kM
sZx`u+
public void splitterStop() ZyM7)!+kPa
{ /q,vQ[R/
bStop = true; '8Cg2v5&w
} xv"v='
dBw7l}
/:tzSKq}
} Al1_\vx7
x(n|zp ("
w_h{6Kc<
/* %oB0@&!mS
**FileAccess.java /!?b&N/d)
*//文件访问(定位，写) \o*w#e[M
package NetFox; +E^2]F7Zk
import java.io.*; JC0#pU;
R_D&"&
)T6:@n^]h
public class FileAccessI implements Serializable{ fMIRr5
6f2?)jOW^N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 15@2h
RandomAccessFile oSavedFile; `dw">z,
long nPos; |a#=o}R_
{#st>%i
mPU}]1*p
public FileAccessI() throws IOException AR!v%Z49i
{ |}L=e.
this("",0); uH?dy55Y
} No"i6R+
tm/=Oc1p
ny{S&f
public FileAccessI(String sName,long nPos) throws IOException j,Mbl"P
{ ^KdT,^6T
oSavedFile = new RandomAccessFile(sName,"rw"); F!3p )?
this.nPos = nPos; #K0/ >W
oSavedFile.seek(nPos); tA^+RO4
} 9Nps<+K
;O1jf4y
wK0x\V6dJ
public synchronized int write(byte[] b,int nStart,int nLen) Td,d9M
{ s>:gL,%c
int n = -1; *v%gNq
try{ -.r"|\1X
oSavedFile.write(b,nStart,nLen); X&HYWH'@,
n = nLen; T_!F I29
} (u^8=#
catch(IOException e) Cu5_OJ
{ k;jl3GV
e.printStackTrace (); *Lxt{z`9
} 2<9K}Of
w,X)g{^T
XlD=<$Nk7
return n; p6NPWaBR
} !@])Ut@tN
yZ7)|j
2*^=)5Gj-h
} qE3Ud:j
@54$IhhT~
>]anTF`d
/* }cI-]|)|2
**SiteInfoBean.java X31%T"
*/ EcX7wrl9x
package NetFox; jygUf|
%TRJ
Q|P M6ta
public class SiteInfoBean { W!T[ ^+
b:'8_jL
lz6CK
private String sSiteURL; //Site's URL (SQGl!Lai0
private String sFilePath; //Saved File's Path IJKdVb~
private String sFileName; //Saved File's Name eaNfCXHDN
private int nSplitter; //Count of Splited Downloading File @{{L1[~:0
$[b}r#P
Yr~wsE/
public SiteInfoBean() ?$ov9U_
{//nSplitter的缺省值为5 8RuW[T?
//default value of nSplitter is 5 Tc!n@!RA|
this("","","",5); 6W
} 88<d<)7t
?/1LueC:
]mi\Y"RO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7Y-Q, ?1
{ w0@XJH:P
sSiteURL= sURL; w2V:x[
sFilePath = sPath; cUP1Uolvn
sFileName = sName; \!jz1`]&{
this.nSplitter = nSpiltter; -hfkF+=U'
nh0gT>a>@
^i8biOSZu
} *2N0r2t&
BMQ4i&kF|
Nxl#]
public String getSSiteURL() @:B}QxC
{ qhG2j;
return sSiteURL; ooB9iNo^
} _g9j_ x:=
]8OmYU%6V
<KtL,a=2+
public void setSSiteURL(String value) Het>G{
{ E_$nsM8?
sSiteURL = value; c;]^aaQ+>
} b;*'j9ly
zsd<0^ p\{
/*e<r6
public String getSFilePath() -R1;(n)
{ *kZH~]
return sFilePath; /E{tNd^S
} 4Ozcs'}
%jf|efxo
^*UtF9~%n
public void setSFilePath(String value) [~cz|C#
{ Z eY*5m
sFilePath = value; }#M>CNi'PU
} ;.xKVH/@
vA ZkT"
!a\HdQ
public String getSFileName() UUbO\_&y
{ ps8tr:T^=
return sFileName; y=+OC1k\8
} ^.g-}r8,
Unq~lt%2
I`jG
public void setSFileName(String value) iqB%sIP
{ -vc$I=b;
sFileName = value; kEAF1RP:
} wL]#]DiE
ob9od5Rf
@x A^F%(
public int getNSplitter() MT)q?NcG
{ ./.aLTh
return nSplitter; 5! +{JTXa
} .!lLj1?p
kD1Nq~h2
c3c3T`B
public void setNSplitter(int nCount) ^5?|Dj
{ -`z%<)!Y
nSplitter = nCount; agruS'c g
} r4X\/
} gcO$T`
aMkuyqPf{
?|}qT05
/* kSCpr0c
**Utility.java vpdPW%B
*/ :f_oN3F p
package NetFox; luac
2~ETu&R:
9jx>&MnWs
public class Utility { 3fZoF`<a
pEN`6*
BXxJra/V
public Utility() q@VIFmqY!
{ +!nf?5;
!Z{7X ^
Buq(L6P9r
} -'WR9M?fq
OR'e!{
//线程睡眠 usoyH0t!?
public static void sleep(int nSecond) "A~D(1K
{ $3ZQ|X[|+
try{ 1~2+w]-kU
Thread.sleep(nSecond); 2S[:mnK
} t@+e#3P!
catch(Exception e) .A6pPRy e
{ H0t#J
e.printStackTrace (); 6L Fhhl^
} `jhbKgR[
} u$ o19n
9oP
//日志 FLkZZ\
public static void log(String sMsg) cf"!U+x
{ 4W E)2vkS
System.err.println(sMsg); G@T_o4t
} m@L>6;*
*g:Dg I 2
b{x/V9&|
public static void log(int sMsg) .>_%12>
{ L7xiq{t`Y
System.err.println(sMsg); K9nW"0>
} ^)|tf\4
} Su +<mW
mT|r:Yr:
el<[Ng[
/* Klu0m~X@
**TestMethod.java j9/iBK\Y
*/ q8GCO\(
package NetFox; ggfCfn
7[R`52pP
fti0Tz'
public class TestMethod { {`>pigo
>,)U46
(58r9WhS
public TestMethod() 889^P`Q5
{ ///xx/weblogic60b2_win.exe jsKKg^g
try{ K,P`V &m?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AnZy oa
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u,`V%J?vW
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4Y G\<Zf
fileFetch.start(); QMDkkNK
} U`)d `4"
catch(Exception e){e.printStackTrace ();} =dWqB&
Gsm.a
9"M-nH*<
} /7.//klN
2@N-#x'
Q } 0_}W
public static void main(String[] args) R"z}q(O:
{ :#N]s
new TestMethod(); 1@~ 1vsJ
} jPc,+?
} }`76yH^c
点击下载更多相关资料