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)); -+'fn$
} YL)epi^
for(int i=0;i<nEndPos.length-1;i++) lZY0A#
{ AoaRlk-#
nEndPos = nStartPos[i+1]; E&\dr;{7
} 0{ZYYB&"~J
nEndPos[nEndPos.length-1] = nFileLength; qk;vn}auD]
} 4(VVEe
} ho1Mo
W"m\|x
A@8Ot-t:\2
//启动子线程 ;XJK*QDN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r'kUU]j9
for(int i=0;i<nStartPos.length;i++) Dq#/Uw#
{ |H:JwxH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .6,+q2tyk,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (xp<@-
nStartPos,nEndPos,i); Ywj=6 +;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CDDx %#eG>
fileSplitterFetch.start(); 7x/S4Gs'4
} 4G:I VK9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]s*Fs]1+H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7eQE[C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j\^0BTZ
nEndPos = " + nFileLength); Oz\mIVC#
// fileSplitterFetch[nPos.length-1].start(); R W=<EF&
&1O!guq%
y$n7'W6
//等待子线程结束 \2?p
//int count = 0; 6^W6As0
//是否结束while循环 Kn9O=?Xh;
boolean breakWhile = false; +Zaew679
~R;9a"nr
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while(!bStop) jlmP1b9
{ HT]v S}s
write_nPos(); _(CuuP$`I
Utility.sleep(500); %X)i-^T
breakWhile = true; ~s}0z&v^te
b-/ztZ@u
%+WIv+<
for(int i=0;i<nStartPos.length;i++) 'Zq$W]i
{ j3Ng] @N
if(!fileSplitterFetch.bDownOver) u N%RB$G
{ _eB?G
breakWhile = false; ep"YGx[V
break; 64Ot`=A"
} lpW|GFG
} )$V&Nf
if(breakWhile) vepZod}D
break; q<Zdf
;5wmQFr
`w_?9^7mH
//count++; &cjE+
//if(count>4) =)56]ki}
// siteStop(); U'pm5Mc\q
} Zk#^H*jgx
z3l=aAw8
P;&rh U^[
System.err.println("文件下载结束！"); <Tq&Va_w
} 0nkon3H
catch(Exception e){e.printStackTrace ();} aR }|^ex
} *wNX<R.
ryz [A:^G
^*;{Uj+O~Y
//获得文件长度 G;:D6\
public long getFileSize() oo{5:
{ \z}/=Qgc
int nFileLength = -1; ]!>ThBMa
try{ Yp8~wdm
URL url = new URL(siteInfoBean.getSSiteURL()); /h4 ::,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pRsYA7Ti
httpConnection.setRequestProperty("User-Agent","NetFox"); <Sxsmf0"
cz8%p;F:
m6%csh-N1
int responseCode=httpConnection.getResponseCode(); `O-LM e
if(responseCode>=400) F{1;~Yg%
{ }$K2h*
processErrorCode(responseCode); %-~W|Y
return -2; //-2 represent access is error +39Vxe:Oy
} uV]4C^k;`[
,hj5.;M
zVLv-U/=d
String sHeader; ?[4!2T,Ca
,&S^Ryc
U @Il:\I
for(int i=1;;i++) [OI&_WIw
{ 7wt2|$Qz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #1MEmt
//Utility.log(in.readLine()); ,2F4S5F~rC
sHeader=httpConnection.getHeaderFieldKey(i); 8^fkY'x
if(sHeader!=null) JPS7L}Kv
{ MCamc
if(sHeader.equals("Content-Length")) {VC4rA
{ &9CKI/K:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x4SI TY
break; 1a#oJU
} By=/DVm)=
} qyP|`Pm4
else zy(i]6
break; 2 }QD>
} 0y$aGAUm
} b\zRwp
catch(IOException e){e.printStackTrace ();} >uN`q1?l'
catch(Exception e){e.printStackTrace ();} &a?&G'?
&"dT/5}6
KKm0@Y
Utility.log(nFileLength); %0]vW;Q5
W)"PYC4
6qA48:/F=
return nFileLength; _=c>>X
} +"Pt?k
k^q}F%UV
bl|k6{A
//保存下载信息（文件指针位置） sQ65QJtt0A
private void write_nPos() ; 6Wlu3I
{ P5;LM9W
try{ W11Wv&
output = new DataOutputStream(new FileOutputStream(tmpFile)); sIuk
output.writeInt(nStartPos.length); ;!4Bw"Gg
for(int i=0;i<nStartPos.length;i++) p*10u@,
{ ~Mv@Bl
// output.writeLong(nPos); 6KiI3%y?0
output.writeLong(fileSplitterFetch.nStartPos); Xtqjx@ye
output.writeLong(fileSplitterFetch.nEndPos); T ,, Ao36
} *uR&d;vg.8
output.close(); kJ6=T6s
} NiU}A$U
catch(IOException e){e.printStackTrace ();} _S:6;_bz
catch(Exception e){e.printStackTrace ();} !1f8~"Z
} z`-?5-a]I
+zxj-diM
u,0N[.&N
//读取保存的下载信息（文件指针位置） xq:.|{HUk
private void read_nPos() <dx xXzLT
{ _//)|.6c3
try{ F_ ~L&jHP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =z'w-ARy
int nCount = input.readInt(); DSY:aD!
nStartPos = new long[nCount]; ZF :e6em
nEndPos = new long[nCount]; mj0{Nd
for(int i=0;i<nStartPos.length;i++) 37)Dx
{ *F+t`<2
nStartPos = input.readLong(); w]n20&
nEndPos = input.readLong(); :.!]+#Me
} 96aA2s1
input.close(); :>to?~Z1
} dzZ74FE!t
catch(IOException e){e.printStackTrace ();} yH>`Kbf T
catch(Exception e){e.printStackTrace ();} i<|5~tm
} @psyO]D=j%
[B9'/:
NLFSw
private void processErrorCode(int nErrorCode) 0bxB@(NO
{ #Ag-?k
System.err.println("Error Code : " + nErrorCode); ko2Kz k
} |w2H5f{fR
gnmKh>0@6o
J=4R" _yo
//停止文件下载 Efi@hdEV
public void siteStop() Y|J\,7CM
{ g(t"+ P
bStop = true; &| %<=\
for(int i=0;i<nStartPos.length;i++) .lfKS!m2
fileSplitterFetch.splitterStop(); _[-+%RP
IM&2SSmYNH
&Zl$7
} $:"r$7
} 9l2,:EQ*
//负责部分文件的抓取 &^e%gU8!\
**FileSplitterFetch.java }f)$+mi
*/ hoI?,[@F
package NetFox; J#B% #X
{S(d5o8
>TUs~
import java.io.*; c6sGjZdR
import java.net.*; `_sc_Y|C!
pN/)$6=
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public class FileSplitterFetch extends Thread { y0qrl4S)v
vz:P2TkM
Ed9ynJ~)X
String sURL; //File URL W HO;;j
long nStartPos; //File Snippet Start Position }l&Uh&B`
long nEndPos; //File Snippet End Position Vh^fbv`?
int nThreadID; //Thread's ID yfeX=h
boolean bDownOver = false; //Downing is over )n 1b
boolean bStop = false; //Stop identical Ddde,WJA
FileAccessI fileAccessI = null; //File Access interface Z<ozANbk
oK&LYlU
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $5y%\A
{ %pgie"k
this.sURL = sURL; jr{C/B}
this.nStartPos = nStart; $$~x: iN
this.nEndPos = nEnd; @\v,
nThreadID = id; /2-S/,a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v!?bEM3D
} n'=-bj`
(&0%![j&
8<M'~G%CEq
public void run() mh]'/C_*<w
{ 5R}Qp<D[^
while(nStartPos < nEndPos && !bStop) -4`Wkkhu
{ emOd<C1A
q}e"E cr
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try{ EZaWEW
URL url = new URL(sURL); fv_}7t7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {]<l|qK
httpConnection.setRequestProperty("User-Agent","NetFox"); zu'Uau
String sProperty = "bytes="+nStartPos+"-"; Ql a'vcT
httpConnection.setRequestProperty("RANGE",sProperty); !Uz{dFJf;
Utility.log(sProperty); 3}=r.\]U
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1C\OL!@L
InputStream input = httpConnection.getInputStream(); D_ xPa
//logResponseHead(httpConnection); !TY9\8JzV
|t*(]U2O0
t m?[0@<s
byte[] b = new byte[1024]; n"8vlNeW
int nRead; IY6DZP
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 24PEt%2
{ ,80qwN,
nStartPos += fileAccessI.write(b,0,nRead); /e :V44
//if(nThreadID == 1) >f#P(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w~a^r]lPW
} PVHJIB
*LpEH,J
>_P7k5Y^
Utility.log("Thread " + nThreadID + " is over!"); D-e0q)RSU
bDownOver = true; G%w.Z< qy
//nPos = fileAccessI.write (b,0,nRead); )orVI5ti
} 9Z]~c^UB
catch(Exception e){e.printStackTrace ();} o&P}GcEIw
} $&/JY
} n/#zx:d?
3ny>5A!;2
}S51yDVG_
//打印回应的头信息 tFt56/4
public void logResponseHead(HttpURLConnection con) t!QuM_i3
{ jY%&G#4
for(int i=1;;i++) 6nh!g
{ |niYN7 17
String header=con.getHeaderFieldKey(i); B*btt+6
if(header!=null) _#@n^c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k`JP
Utility.log(header+" : "+con.getHeaderField(header)); ntbl0Sk
else hc OT+L>
break; L;zwqdI
} k8H@0p
} {Vw+~8
CsHHJgx
K}"xZy Tm1
public void splitterStop() x8k7y:
{ 's>
bStop = true; &5puGnTZ
} [P.M>"c\
j#QJ5(#
P8!ON=
} m3W:\LTTp
koOkm:(,
Jb~$Vrdy
/* H'k$<S
**FileAccess.java Y,Dd}an
*//文件访问(定位，写) 3qJOE6[}%
package NetFox; hw! l{yv
import java.io.*; C'&)""3d
!z">aIj\6
}5c%v1
public class FileAccessI implements Serializable{ "%fh`4y3\
gY\X?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -&4>>h9_
RandomAccessFile oSavedFile; (5- w>(
long nPos; 68Po`_/s
O b'B?
j6v|D>I
public FileAccessI() throws IOException -!MrG68
{ FjRt'
this("",0); /(IV+
} 8G$ %DZ $
m(CW3:|
.nN=M>#/
public FileAccessI(String sName,long nPos) throws IOException 4x7(50hp#
{ 6. N?=R
oSavedFile = new RandomAccessFile(sName,"rw"); ]<b$k
this.nPos = nPos; 0K/Pth"*
oSavedFile.seek(nPos); k(LZ,WSR
} HJ#3wk"W
,/0Q($oz
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public synchronized int write(byte[] b,int nStart,int nLen) \kSoDY`l&
{ Zoe>Ow8mE`
int n = -1; y/=:F=H@w
try{ :})(@.H
oSavedFile.write(b,nStart,nLen); yg({g "
n = nLen; m$<LO%<~p
} HYVSi3[
catch(IOException e) MKVz'-`u
{ tGt/=~n9
e.printStackTrace (); iMG)zPj
} %smQ`u|
^(z7?T
*+(t2!yFmE
return n; .OhpItn
} m2c>RCq
@1+C*
:QKxpHi
} t~5m[C[`w
+m?;,JGt
&\<!{Y<'
/* MJ5Ymt a
**SiteInfoBean.java HIiMq'H^
*/ 1B}q?8n
package NetFox; 590.mCm
&gF*p
m]H[$Q
public class SiteInfoBean { OAigq6[,
Zop3[-
x)evjX=q
private String sSiteURL; //Site's URL A8,9^cQ]
private String sFilePath; //Saved File's Path b-*3]gB
private String sFileName; //Saved File's Name &O|!w&
private int nSplitter; //Count of Splited Downloading File :`u?pc27Sm
a=ye!CN^
^gw htnI
public SiteInfoBean() [6 d~q]KH
{//nSplitter的缺省值为5 ^RL#(O
//default value of nSplitter is 5 nc<wDE6
this("","","",5); 5x$/.U
} `O~NT'Ed8
LDg"s0n#
.'`7JU#{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RLnsy,
{ "53'FRj_\
sSiteURL= sURL; jA'qXc+\
sFilePath = sPath; mL5Nu+#
sFileName = sName; b\6)whh
this.nSplitter = nSpiltter; .<xzf4C
&[u>^VO8
So?.V4aD_
} s*'L^>iZ
3k YVk
N$'/J-^
public String getSSiteURL() 2!-?
{ Q1ox<-
return sSiteURL; 7RXTQ9BS
} 1Yr&E_5/
N5W;Zx]
b5!\"v4c
public void setSSiteURL(String value) NO$n-<ag
{ |E{tS,{OhJ
sSiteURL = value; u_kcuN\Sq
} ceiUpWMu,
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M't~/&D#
public String getSFilePath() |X}H&wBWo
{ j[E8C$lW
return sFilePath; [cJQ"G '
} %62W[Oh5
$O\I9CGr$
>Xz=E0;^Ua
public void setSFilePath(String value) ? PIq/[tk
{ hMcSB8?
sFilePath = value; g(X-]/C{
} 1yFVF
L#
yQP!Vt^
public String getSFileName() aJ!(c}N~97
{ B: '}SA{
return sFileName; Z`_`^ \"
} w@K4u{|
|6qxRWT"
I JPpF`
public void setSFileName(String value) It5U=PU
{ M lv
sFileName = value; 1\'?.
} <5Ye')+
os:/-A_m
]^f7s36
public int getNSplitter() 8|-j]
{ gKp5*
return nSplitter; S%NS7$`a
} jruXl>T!U
6[b?ckvi
Y 6NoNc]h
public void setNSplitter(int nCount) SHoov
{ su?{Cj6*
nSplitter = nCount; 96V@+I
} ym\AVRO{
} 8LI aN}
dwH8Zg$B
T9s$IS,
/* P M x`PB
**Utility.java d65fkz==A)
*/ \tpJ
package NetFox; PZT]H?
*\-R&8
asT/hsSNS
public class Utility { {2A| F{7>
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4$5d*7
public Utility() Dw%V.J/&o
{ 2 }9of[
(31ia"i%
c `[,>
} U@;W^Mt
/.knZ_aJ!
//线程睡眠 V`ODX>\
public static void sleep(int nSecond) cWNZ +Q8Y
{ `6R.*hq
try{ [lU0TDq
Thread.sleep(nSecond); MD"a%H#p
} bF85T(G
catch(Exception e) )aV\=a |A
{ "mbjS(-eg
e.printStackTrace (); }NH\Q$IU
} fXL&?~fS
} QU#u5sX A
X@["Jjp
//日志 Z+gG.|"k
public static void log(String sMsg) '8k{\>
{ '7Ad:em
System.err.println(sMsg); ^R g=*L
} ^|b]E
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6w?l I
public static void log(int sMsg) Z(|@C(IL0\
{ mQbpv'N
System.err.println(sMsg); Mk3~%`
} uVSc1MS1
} 0h3-;%
tRUGgf`
?(t{VdZSzQ
/* _mEW]9Sp
**TestMethod.java H3}eFl=i2
*/ hJ)\Vo
package NetFox; 7EfLd+
=6sA49~M
+i\ +bR
public class TestMethod { q7z;bA
7Gos-_s
>V01%fLd
public TestMethod() I^u$H&
{ ///xx/weblogic60b2_win.exe %',bCd{QW
try{ A"Prgf eT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p{V_}:|=Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L~Hl?bK
SiteFileFetch fileFetch = new SiteFileFetch(bean); `wMHjcUP
fileFetch.start(); ]-rhc.Gk@1
} Dc1tND$X3g
catch(Exception e){e.printStackTrace ();} u|G&CV#r
fwN'5ep
6Mh;ld@
} F2N)|C<
>*wF~G*k
wU"0@^k]<
public static void main(String[] args) hoj('P2a#n
{ |}?o=bO
new TestMethod(); CnXl 7"
} ,/bSa/x`
} bG|aQ2HW
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