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)); xK f+.6 wz
} l%fl=i~oN
for(int i=0;i<nEndPos.length-1;i++) "&~Um U4CN
{ *@< jJP4
nEndPos = nStartPos[i+1]; 6K6ihR!d
} W/+0gh7`,(
nEndPos[nEndPos.length-1] = nFileLength; _F$?Z
} :'03*A_[
} zc_3\N
is,_r(S
y~w$>7U.
//启动子线程 $Khc?v
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :(Gg]Z9^8
for(int i=0;i<nStartPos.length;i++) eG<32$I
{ F C"dQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q;U[f6JjE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gC?k6)p$N
nStartPos,nEndPos,i); 4GJsVA(d|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /PO5z7n0J
fileSplitterFetch.start(); 3;&N3:,X
} VrHFM(RNe
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w%htY.-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0@>3fR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F2#^5s(
nEndPos = " + nFileLength); N.uw2Y%
// fileSplitterFetch[nPos.length-1].start(); UGIyNMY
'_2~8w
(%".=x-
//等待子线程结束 _d:l1jD
//int count = 0; 0h* AtZv_
//是否结束while循环 tjGQ0-Lo
boolean breakWhile = false; 3*ZE``
*9G;n!t
\'shnzs
while(!bStop) RszqDm
{ =OCHV+m
write_nPos(); 1^vN?#Kt
Utility.sleep(500); P9gIKOOx#4
breakWhile = true; `CO?} rW
[H!V
8uNq353
for(int i=0;i<nStartPos.length;i++) vU::dr
{ i0hF9M
if(!fileSplitterFetch.bDownOver) XB2[{XH,
{ mI-$4st]
breakWhile = false; w18kTa!4@
break; C"K(-/
} Y*0mC"n}
} f$R]m2
if(breakWhile) |GLa`2q|
break; C/!kMMh>vV
E`$d!7O
ftRf~5d2
//count++; |-bAzt
//if(count>4) *1|&uE&_R
// siteStop(); aVEg%8
} ;>bcI).
4vF1
XI@;;>D1=U
System.err.println("文件下载结束！"); ,iV|^]X3$/
} *Mk5*_
catch(Exception e){e.printStackTrace ();} u.43b8!
} 26?yEd6^Z
G[GSt`LVS`
#fd;]
//获得文件长度 I'm.+(1m,
public long getFileSize() r Z%l?(
{ w*n@_n={
int nFileLength = -1; )cxLpTr
try{ )ERmSWq/u
URL url = new URL(siteInfoBean.getSSiteURL()); M|xd9kA^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4-1=1)c*
httpConnection.setRequestProperty("User-Agent","NetFox"); u[k0z!p_ c
e'Njl?>3
Fu].%`*xJ
int responseCode=httpConnection.getResponseCode(); ei%L[>N
if(responseCode>=400) 8cI<~|4_
{ jOV,q%)^,:
processErrorCode(responseCode); KPTp91
return -2; //-2 represent access is error +es|0;Z4yP
} =MMU(0 E
j S~Wcu
H}vq2|MN
String sHeader; W~b->F
?QR13l(
^N#z&oh
for(int i=1;;i++) Vh=10Et
{ F)XO5CBK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;XAj/6pm
//Utility.log(in.readLine()); _=$:<wIE[
sHeader=httpConnection.getHeaderFieldKey(i); JlaT -j
if(sHeader!=null) H+lBb$
{ ^I!u H1G
if(sHeader.equals("Content-Length")) <9Sg,ix't
{ : ZehBu
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ry_"sow4
break; {_[\k^98>
} df9jT?l
} {XR3L'X
else A-S!Z2m\
break; <+3-(&
} S1SsJo2\
} a]NH >d
catch(IOException e){e.printStackTrace ();} s[2>r#M
catch(Exception e){e.printStackTrace ();} ?OD43y1rzd
h_*!cuH
;cpQ[+$nKp
Utility.log(nFileLength); u/6b.hDO
7j,u&%om
nNj<!}HvV
return nFileLength; (?y (0%q
} o!$O+%4
;;f&aujSHD
"fH"U1Bw
//保存下载信息（文件指针位置） V =9
private void write_nPos() Ng,<4;
{ MqKf'6z
try{ LWX,u
output = new DataOutputStream(new FileOutputStream(tmpFile)); YZ\a#s,0
output.writeInt(nStartPos.length); rP%B#%;S"
for(int i=0;i<nStartPos.length;i++) vHmsS\\~9
{ .+#<~Jv
// output.writeLong(nPos); )y#~eYn
output.writeLong(fileSplitterFetch.nStartPos); !TwH;#U w
output.writeLong(fileSplitterFetch.nEndPos); 3{/[gX9
} <<vT"2Q]
output.close(); CT2L }5L&
} :@oy5zib
catch(IOException e){e.printStackTrace ();} e09('SON(
catch(Exception e){e.printStackTrace ();} oj$^87KX
} Ew,1*WK!
W`k||U9
0pW?v:!H
//读取保存的下载信息（文件指针位置） VC T~"T2R
private void read_nPos() }eLnTi{
{ T*3>LY+bb
try{ /\-iV)h1@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~tM+!
int nCount = input.readInt(); ~E^lKe
nStartPos = new long[nCount]; }<=4A\LZ
nEndPos = new long[nCount]; {3H)c^Q
for(int i=0;i<nStartPos.length;i++) r5wy]z^
{ 0x1#^dII
nStartPos = input.readLong(); ;;{!wA+"D
nEndPos = input.readLong(); rEfo)jod
} :Sc"fG,g)
input.close(); #)7THx/=
} "54t7
catch(IOException e){e.printStackTrace ();} 0Z,a3)jcc
catch(Exception e){e.printStackTrace ();} @b]?Gg
} jM07&o]D
Nk ~"f5q7
Bsc&#
private void processErrorCode(int nErrorCode) 2leTEs5aK`
{ OF_g0Zu
System.err.println("Error Code : " + nErrorCode); _X/`7!f
} Z8xKg
!ma%Zk
H4Lvw8G
//停止文件下载 +#@)C?G,TF
public void siteStop() ;jZfVRl
{ nMT"Rp
bStop = true; sk>E(Myo
for(int i=0;i<nStartPos.length;i++) 1[U`,(C1
fileSplitterFetch.splitterStop(); sCrOdJ6|
XUK!1}
-#agWqUM|T
} I/vQP+w O
} Z!eW_""wp
//负责部分文件的抓取 H5J1j*P<d
**FileSplitterFetch.java 0<4Nf]i
*/ Mv%"aFC
package NetFox; +J;T= p
;GF+0~5>
P;7 Y9}
import java.io.*; aFf(m-
import java.net.*; +5xVgIk#
g*-%.fNA
*^=zQ~
public class FileSplitterFetch extends Thread { M4rK
i+XHXpk
vDit&Lh{T
String sURL; //File URL @en*JxIM
long nStartPos; //File Snippet Start Position gi#g)9HG
long nEndPos; //File Snippet End Position WMk;-,S!)
int nThreadID; //Thread's ID %}/|/=
boolean bDownOver = false; //Downing is over 2T&n6t$p
boolean bStop = false; //Stop identical o4F?Rx,L
FileAccessI fileAccessI = null; //File Access interface 6(=>!+xpRr
`SM37({c
S:YQVj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException FofeQ
{ W^8MsdM
this.sURL = sURL; e4mAKB s!
this.nStartPos = nStart; QFX/x
this.nEndPos = nEnd; Tk~Y
nThreadID = id; $z \H*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 XN %tcaY
} sn-P&"q
!E.CpfaC
\\iX9-aI<
public void run() mnm7{?#[
{ /c|X:F!;X#
while(nStartPos < nEndPos && !bStop) W<tw],M-#
{ ?Jy/]j5fI
AU3>v
4qvE2W}&
try{ 1a@b-V2 d&
URL url = new URL(sURL); [$e\?c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `x:8m?q05
httpConnection.setRequestProperty("User-Agent","NetFox"); 9?38/2kX4
String sProperty = "bytes="+nStartPos+"-"; ^_5t5>
httpConnection.setRequestProperty("RANGE",sProperty); }BN!Xa
Utility.log(sProperty); DNu-Ce%
pSKwXx
q.s'z}
InputStream input = httpConnection.getInputStream(); }-N4D"d4o
//logResponseHead(httpConnection); P0<)E
kkU#0p?7
#w1E3ahaX
byte[] b = new byte[1024]; tYUg%2G
int nRead; WWgJ !Uz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q~6a$8+t
{ Qy7pM8~h
nStartPos += fileAccessI.write(b,0,nRead); 8{DW$ZtR
//if(nThreadID == 1) v7b+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?X^.2+]*&
} 0@>
8/"R&yAh
,"U|gJn|^
Utility.log("Thread " + nThreadID + " is over!"); .Ge`)_e
bDownOver = true; 6(8zt"E
//nPos = fileAccessI.write (b,0,nRead); /K :H2?J
} D $&6 8
catch(Exception e){e.printStackTrace ();} vWVQ8S.
} W4&Itj
} 7RCVqc"
K_GqM9
h pKrP
//打印回应的头信息 ,Q,3^v-
public void logResponseHead(HttpURLConnection con) PM^Xh*~
{ RgSB?
for(int i=1;;i++) mt\pndTy7!
{ -Ic<.ix
String header=con.getHeaderFieldKey(i); s8+{##"1 q
if(header!=null) -'rb+<v
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9S/X,|i
Utility.log(header+" : "+con.getHeaderField(header)); "Tnmn@
else S N;1F
break; cpu|tK.t
} _#y=T20'3
} F0KNkL>&g
S.|%dz
'<1Q;3Ho
public void splitterStop() p+}eP|N
{ ZO&F15$P
bStop = true; O2S{*D={
} GzjC;+W
C]M{
|vY|jaV}
} j"9Zaq_
hx hs>eY
:Fdk`aC
/* Rf TG 5E)
**FileAccess.java G5*_
*//文件访问(定位，写) 5!qLJmd=
package NetFox; TlpQ9T
import java.io.*; u"-."_
O5dBI_
N >k,"=N/
public class FileAccessI implements Serializable{ #K\;)z(?
Y0g6zHk7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -~_;9[uV
RandomAccessFile oSavedFile; i+~H~k}"X
long nPos; N:UA+
/Y8{?
e!P]$em|1E
public FileAccessI() throws IOException %:Y'+!bX
{ [cT7Iqip
this("",0); =po5Q6@i
} Z[9f8/6<b
gPF5|% 3)
tx]!|x" F
public FileAccessI(String sName,long nPos) throws IOException Q#}c5TjVr
{ _F3= H]P
oSavedFile = new RandomAccessFile(sName,"rw"); D`NQEt"(
this.nPos = nPos; >/7[HhBT
oSavedFile.seek(nPos); :JCe,1!3@
} X-_0wR
Jqqt@5Ni
Kbcr-89Gv~
public synchronized int write(byte[] b,int nStart,int nLen) p"QV| `
{ 9On(b|mT
int n = -1; M~-jPY,+
try{ Z'_EX7r
oSavedFile.write(b,nStart,nLen); T9]:, z
n = nLen; 0ae}!LO
} -}P/<cu:
catch(IOException e) @^^,VgW[
{ g/OL^A
e.printStackTrace (); no8FSqLUS~
} PZhpp"
^spASG-o
zwdi$rM5
return n; Kr74|W=
} OB\jq!"
ItwJL`
b_-?ZmV^r
} hlBqcOpkKg
8&++S> <
#<gD@Jybu
/* sU;aA0kz
**SiteInfoBean.java T<~?7-O"
*/ u;=a=>05IR
package NetFox; R;F z"J
bj U]]
A9ru]|?
public class SiteInfoBean { @1+({u#B
IW- BY =C
.u&GbM%Ga
private String sSiteURL; //Site's URL #H&`wMZZ:
private String sFilePath; //Saved File's Path hV[=
private String sFileName; //Saved File's Name b[ .pD3
private int nSplitter; //Count of Splited Downloading File 2JLXDkZ
F@jyTIS^
c~{)vL0K
public SiteInfoBean() DT>Giic
{//nSplitter的缺省值为5 ys Td'J
//default value of nSplitter is 5 \,yX3R3}.~
this("","","",5); Xjnv8{X
} F;<cG`|Rx
d9yfSZ
nZ~J&QK-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "CF{Mu|Q=
{ 3NxwQ,~
sSiteURL= sURL; G|.5.FK^
sFilePath = sPath; F}{uY(hv"[
sFileName = sName; V]0~BV
this.nSplitter = nSpiltter; H<bB@(i
,[|4{qli\
wEMg~Hh
} 7&{[Y^R]"
@/0-`Y@?
~91) DNaE
public String getSSiteURL() o+ 0"@B
{ R[{s\
return sSiteURL; }='1<~0
} tP]-u3
gDBdaxR<
'n0u6hCSb
public void setSSiteURL(String value) T{Y;-m
{ c(G;O)ikS
sSiteURL = value; CJ#1j>
} DSc:>G
89X`U)Ws
3CArUP
public String getSFilePath() %W:]OPURK
{ kqyPb$Wy
return sFilePath; l8Ks{(wh
} Zm~oV?6
Ht!]%
+-+%6O<C
public void setSFilePath(String value) UA]U_P$c
{ (!^;ar^
sFilePath = value; y?*4SLy
} <u%&@G$F>
tNbZ{=I>
^-GzWT
public String getSFileName() 2%*mL98WK
{ N56/\1R
return sFileName; MeXGE
} )T26cT$
)S2GPn7
.PJCBTe
public void setSFileName(String value) k1)=xv#S
{ qH1&tW$
sFileName = value; !HPye@Ua
} ]E!b&
,U^V]jC
d iGkwKj
public int getNSplitter() pNIu;1M5a
{ (viGL|Ogn
return nSplitter; u>W:SM
} Q5~Y;0'
P>s3Rh3:
=@EX!]=x
public void setNSplitter(int nCount) :$J4T;/{
{ *8?0vkZZ2
nSplitter = nCount; AV%t<fDG#
} =2rkaBFC
} <+\ w.!
PBo;lg`
]> dCt<
/* ub,GF?9
**Utility.java -cqR]'u
*/ U3UDA
package NetFox; *t3uj
?f\ ~:Gm/
Nxd<#p
public class Utility { Zj]jE%AT
rE[:j2HF
zF-R$_]av
public Utility() aUTXg60l*
{ $>csm
?7]UbtW[
`: R7jf
} ]W9{<+&
)EhRqX9
//线程睡眠 U6/$CH<pe
public static void sleep(int nSecond) [W#M(`}D
{ EO: VH
try{ K#>@T<
Thread.sleep(nSecond); Q6lC:cB<
} ,K>q{H^
catch(Exception e) gf\F%VmSN
{ c?H@HoF
e.printStackTrace (); Z| f~
} V9%!B3Sb
} )] C"r_
2QN ~E
//日志 QRL+-)DMc
public static void log(String sMsg) ^0fe:ac;
{ WH6Bs=G\}
System.err.println(sMsg); [42EqVR
} ![l`@NH[U
)U5Ba^"fI
7q;wj~
public static void log(int sMsg) s-"oT=
{ S+*g
System.err.println(sMsg); px>g
} EjDr
} A]_5O8<buW
x3L0;:Fx8P
&RL j^A!
/* GJo`9
**TestMethod.java ^2}p%j>
*/ hqwDlapTt
package NetFox; `vc?*"
C=zc6C,
nSR<(-j!
public class TestMethod { hvo7T@*'
mDX UF~G[
3:ELYn
public TestMethod() ,\^RyHg
{ ///xx/weblogic60b2_win.exe NS3qNj
try{ 57`*5X
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |Zm'!-_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3^-yw`
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9>7w1G#
fileFetch.start(); tuIQiWHbM
} sOb=+u$$9
catch(Exception e){e.printStackTrace ();} ;/s##7qf
trm-&e7q?;
#y>q)Ph
} 5q95.rw
GEbm$\
)gPkL r
public static void main(String[] args) {O"N2W
{ m$!Ex}2
new TestMethod(); D9/PVd&#
} 2{oU5e
} t^5xq8w8
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