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)); aX[1H6&=7
} z3vsz
for(int i=0;i<nEndPos.length-1;i++) MKVfy:g%So
{ )4'x7Qg/
nEndPos = nStartPos[i+1]; M~ i+F0
} Q2[prrk%j
nEndPos[nEndPos.length-1] = nFileLength; k binf
} :p\(y
} /+x#V!zM
wzDk{4U
6HEqm>Yau
//启动子线程 Ha=_u+@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; d Y:|Ef|v(
for(int i=0;i<nStartPos.length;i++) }:RT,<
{ %EJ\|@N:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pT3X/ra
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {w |dM#
nStartPos,nEndPos,i); T<TcV9vM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _X,[]+ziu%
fileSplitterFetch.start(); /slm ]'
} 7|+|\7l#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,TKs/-_?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [w&#+h-q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $KwI}>E4
nEndPos = " + nFileLength); w PG1P'w;
// fileSplitterFetch[nPos.length-1].start(); LL= Z$U $
Uw2,o|=O
|b$>68:
//等待子线程结束 $S6HZG:N
//int count = 0; }XGMa?WR
//是否结束while循环 BrlzN='j}
boolean breakWhile = false; cQ3W;F8|n
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fr}1_0DDz
while(!bStop) ,?xLT2>J_
{ 7xv4E<r2
write_nPos(); ,]PyDq6
Utility.sleep(500); i}/e}s<-6
breakWhile = true; -y&v9OC2-
E ;BPN
sJ))<,e5I
for(int i=0;i<nStartPos.length;i++) [K cki+
{ AfbB~LlBq
if(!fileSplitterFetch.bDownOver) v"P&`1=T
{ Pl rkgS0J
breakWhile = false; ,hpH!J'5f/
break; e2]4a3
} *#&k+{a^2
} |^7f\.oF
if(breakWhile) 8sN#e(@
break; ADv^eJJ|
DS#cm3
a|DsHZ^6^
//count++; Q^z=w![z
//if(count>4) prNhn:j
// siteStop(); IVI~1~
} ./'~];&
FAQr~G}
sU) TXL'_!
System.err.println("文件下载结束！"); s<[A0=LH
} ,O:EX0
catch(Exception e){e.printStackTrace ();} :a_BD
} H~A"C'P3#
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;{<aA 5
//获得文件长度 q,[k7&HS
public long getFileSize() C`\9cej
{ s kN9O"^A
int nFileLength = -1; $> "J"IX
try{ k:b/Gq`
URL url = new URL(siteInfoBean.getSSiteURL()); Q~Ay8L+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v,/[&ASz
httpConnection.setRequestProperty("User-Agent","NetFox"); yXJ]U \ %
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9T(L"9r-e
int responseCode=httpConnection.getResponseCode(); ;B&^yj&;
if(responseCode>=400) e^j<jV`1
{ c_ La^HS
processErrorCode(responseCode); bGbqfO`
return -2; //-2 represent access is error "j{i,&Y$_
} 9n1ZVP.ag
"(s6aqO$
K&=D-50%
String sHeader; PJzc=XPU
^_v[QV
AY#wVy
for(int i=1;;i++) t)YUPDQ@J
{ 6X/wdk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qE )Y}oN
//Utility.log(in.readLine()); taweGc%~
sHeader=httpConnection.getHeaderFieldKey(i); F\a]n^ Y
if(sHeader!=null) Pm4e8b
{ 3sH\1)Zz
if(sHeader.equals("Content-Length")) g>so R&*
{ 9YB2e84j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (+* ][|T
break; et=7}K]l
} pmD4j8F_
} cv}aS_`f
else <OTWT`G2
break; nqT>qS[Z
} RctU'T
} |,b2b2v?
catch(IOException e){e.printStackTrace ();} zj<ahg%z
catch(Exception e){e.printStackTrace ();} \V,c]I
"!O1j r;
|^R*4;Phe
Utility.log(nFileLength); ((XE\V\}Z
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/ s,tY74'5
return nFileLength; e@E17l-
} #ZJMlJ:q`"
Vtr3G.P^
Ly;I,)w
//保存下载信息（文件指针位置） i}v9ut]B
private void write_nPos() W{ fZ[z
{ @}Zd (o
try{ Gqb])gXpl
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]4`t\YaT
output.writeInt(nStartPos.length); J!{Al
for(int i=0;i<nStartPos.length;i++) mzX;s&N#
{ 'BY-OA#xJ
// output.writeLong(nPos); ?~J i-{#X
output.writeLong(fileSplitterFetch.nStartPos); l<(cd,
output.writeLong(fileSplitterFetch.nEndPos); >!L&>OOx
} [E7MsX
output.close(); d+;gw*_Ei
} O gmSQ
catch(IOException e){e.printStackTrace ();} DECB*9O^
catch(Exception e){e.printStackTrace ();} xACdZB(
} 8$0\J_
wJe?t$ac?
%%%S"$t
//读取保存的下载信息（文件指针位置） {T=52h=e
private void read_nPos() fiVHRSX60
{ )tS-.PrA-
try{ .h4\{|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4*TmlY
int nCount = input.readInt(); qTT,U9]:
nStartPos = new long[nCount]; Tk*w3c"$
nEndPos = new long[nCount]; T>A{qu
for(int i=0;i<nStartPos.length;i++) dH\XO-Z7v
{ >O#grDXb
nStartPos = input.readLong(); 24ux
nEndPos = input.readLong(); 8Hi!kc;f6>
} ^rL_C}YBj-
input.close(); %y&]'A
} <_Eg?ePW#
catch(IOException e){e.printStackTrace ();} %v+=;jw
catch(Exception e){e.printStackTrace ();} lwT9~Hyp
} D'b#,a;V
2C$R4:Ssw)
& ze>X
private void processErrorCode(int nErrorCode) (CJ.BHu]
{ 9@K.cdRjQ
System.err.println("Error Code : " + nErrorCode); .$&Q[r3Lu
} e4`uVq5
a^t?vv
d;7uFh|o
//停止文件下载 m}3gZu]
public void siteStop() ('C7=u&F
{ #]E(N~
bStop = true; ujr(K=E
for(int i=0;i<nStartPos.length;i++) Y ya`&V
fileSplitterFetch.splitterStop(); A(8n
S QY"OBo<e
t P"\J(x
} u,1}h L
} +/rH(Ni
//负责部分文件的抓取 !2tW$BP^
**FileSplitterFetch.java 3GH(wSv9\
*/ }tG3tz0%fX
package NetFox; 2&Jdf
}7s>B24J
HfB@vw^
import java.io.*; OtTBErQNF
import java.net.*; 5GQLd
>9H@|[C
wW2d\Zd&
public class FileSplitterFetch extends Thread { 4/e60jA
~+G#n"Pn
P[ r];e
String sURL; //File URL 47r&8C+&\
long nStartPos; //File Snippet Start Position f )Z%pgB
long nEndPos; //File Snippet End Position t<j^q`;@v
int nThreadID; //Thread's ID amWD-0V
boolean bDownOver = false; //Downing is over zR;X*q"T$4
boolean bStop = false; //Stop identical ?4 S+edX
FileAccessI fileAccessI = null; //File Access interface #]]Su91BA
]y@F8$D!
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yxt[= C
{ yX!HZu;j
this.sURL = sURL; C&~1M}I
this.nStartPos = nStart; =1p8i
this.nEndPos = nEnd; Rp9fO?ZjHt
nThreadID = id; &?,6~qm[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?GA&f2]a
} ORN6vX(1
"LhvzM-<8
"O[j!fG8,
public void run() N587(wZ
{ o>Er_r
while(nStartPos < nEndPos && !bStop) 6w[}&pX"z
{ j*v40mXl`2
? "/ fPV-
m#vL*]c}
try{ w Y
URL url = new URL(sURL); SqA J-_~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A{eLl
httpConnection.setRequestProperty("User-Agent","NetFox"); +rXF{@ l
String sProperty = "bytes="+nStartPos+"-"; E Y<8B3y
httpConnection.setRequestProperty("RANGE",sProperty); sP@X g;]
Utility.log(sProperty); b5G}3)'w
.|qK+Hnc
h}`!(K^;3
InputStream input = httpConnection.getInputStream(); JAjmrX
//logResponseHead(httpConnection); 'XrRhF (
4+;$7"fJ
4mjgt<`
byte[] b = new byte[1024]; Y-mK+12
int nRead; LhXUm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WLa!.v>
{ %+>s#Q2d
nStartPos += fileAccessI.write(b,0,nRead); "syh=BC v
//if(nThreadID == 1) p?D2)(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <*!i$(gn
} U9y|>P\)T
JA)?p{j
tR0pH8?e"
Utility.log("Thread " + nThreadID + " is over!"); z4#(Ze@u~_
bDownOver = true; !" #9<~Q,p
//nPos = fileAccessI.write (b,0,nRead); <h).fX
} PNOGN|D
catch(Exception e){e.printStackTrace ();} oX@ya3!Pz
} )tHaB,
} LVJI_O{fH
7hW+T7u?
._w8J"E5
//打印回应的头信息 :<Y}l-x
public void logResponseHead(HttpURLConnection con) [D-Q'"'A
{ 9^"b*&>P
for(int i=1;;i++) g"s$}5{8:
{ ,#FLM`
String header=con.getHeaderFieldKey(i); 9E2j!
if(header!=null) acP+3u?r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aprm0:Q^
Utility.log(header+" : "+con.getHeaderField(header)); Zn=T#o
else kE8>dmH23
break; Wz4&7KYY
} zya5Jb:Sg
} \Ng\B.IQ
\<Sv3xy&O
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public void splitterStop() p.I.iAk%G^
{ 7(M(7}EKA
bStop = true; w=]Ks'C]
} %W,D;?lEo>
X"gCRn%tn
A[IL H_w
} NjPDX>R\K
^D^4 YJz
p.}Ls)I
/* ]5~s"fnG
**FileAccess.java \!IMaB]
*//文件访问(定位，写) 2sNK
package NetFox; :@W.K5
import java.io.*; NNhL*C[_7
Xs&TJ8a
MV_Srz
public class FileAccessI implements Serializable{ 0]QRsVz+
ETp%s{8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y@2epY?{
RandomAccessFile oSavedFile; j'[m:/
long nPos; ^-FX
yR{x}DbG
b" xmqWa
public FileAccessI() throws IOException CT0l!J~5m~
{ C%*k.$#r!
this("",0); Mb3}7@/[
} %ms'n
-jgysBw+Xb
M/x>51<
public FileAccessI(String sName,long nPos) throws IOException }N_NvY
{ Pe C7
oSavedFile = new RandomAccessFile(sName,"rw"); yC 77c=
this.nPos = nPos; hA\K</h.
oSavedFile.seek(nPos); [."[pY
} `V)Z)uN{0
pa}*E
]yjl~3
public synchronized int write(byte[] b,int nStart,int nLen) 9/+Nj/
{ :o:e,WKxb
int n = -1; %WqNiF0-
try{ {`2R,Jb%S
oSavedFile.write(b,nStart,nLen); E?(xb B
n = nLen; #r PP*
} 7+x? "4
catch(IOException e) ]9}HEu;1M
{ tm7u^9]
e.printStackTrace (); sr@j$G#uW5
} r{L4]|(utY
QwhRNnE=
PoEqurH0
return n; r=yK,d/1
} AiD[SR
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?+T^O?r|O
} >]o}}KF?
.0R v(Y
\om%Q[F7a
/* {3N'D2N
**SiteInfoBean.java L4uFNM]
*/ eZ"1gYqy
package NetFox; Bgmn2-
iC iZJ"
RwS@I/
public class SiteInfoBean { Y>jiXl?&
"c}@V*cO<d
5*[2yKsTi
private String sSiteURL; //Site's URL 7ugZE93!
private String sFilePath; //Saved File's Path O;7)Hjwt
private String sFileName; //Saved File's Name f|u#2!7
private int nSplitter; //Count of Splited Downloading File 7JSNYTH
eNiaM6(J
jA#/Z
public SiteInfoBean() [r/k% <
{//nSplitter的缺省值为5 s;UH]
//default value of nSplitter is 5 PRNoqi3sY
this("","","",5); ~ %B<
} v]B L[/4
;S xFp
gm9mg*aM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5k|9gICyd*
{ i-yy/y-N
sSiteURL= sURL; @ P|LLG'
sFilePath = sPath; OFje+S
sFileName = sName; 1Bxmm#
this.nSplitter = nSpiltter; r! Ay:r
Y.^=]-n,
dMR3)CO
} /%lZu^
|W<+U
:$MG*/Q
public String getSSiteURL() *,BzcZ
{ Vf(6!iRP@
return sSiteURL; };'\~g,1
} nC{%quwh{
Zw wqSyuGf
^&g=u5 d0
public void setSSiteURL(String value) wcDRH)AW.
{ !bV5Sr^
sSiteURL = value; b,8{ X<
} qC'{;ko
_HhbIU
"vtCTl~t
public String getSFilePath() xeGb?DPu
{ \c^45<G2qA
return sFilePath; y^o@"IYu3
} v9T_&
v@#b}N0n
3]?#he
public void setSFilePath(String value) %Qk/_ R1
{ LkQX?2>]
sFilePath = value; O9:U8$*
} Ali9pvE
T6ENtp
)?wJF<[_#
public String getSFileName() ;2Q~0a|
{ vX]Gf4,
return sFileName; ytNO*XoR
} &HSq(te
vzmc}y G
x`6<m!d`
public void setSFileName(String value) P'Q+GRpSw
{ D-N8<:cA
sFileName = value; s=42uKz
} n("0%@ov
" LJq%E
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public int getNSplitter() IUtx!.]4
{ "--t e
return nSplitter; >3&O::]3
} d|4}obCt
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4V~?.
public void setNSplitter(int nCount) "?mJqA
{ ;qBu4'C)T
nSplitter = nCount; T9s2bC.z55
} @gG<le6
} ES40?o*]x
w|Nz_3tI
\(%Y%?dy
/* '? jlH0;
**Utility.java jMpD+Mb
*/ 0>zbCubPH
package NetFox; VsA'de!V4[
WVLHfkN
1IVuSp`{FU
public class Utility { tY <Z'xA?
xCtmXo
E}ZJ)V7
public Utility() A2|Ud_
{ )Y)pmjZaG
xpOg8u5
}K3x
} >a}f{\Q
@/k@WhFZ
//线程睡眠 5ms""LD/
public static void sleep(int nSecond) ]Zmj4vK J
{ <mAhr
try{ gynh#&r
Thread.sleep(nSecond); uIZWO.OdU
} "U7qo}`I
catch(Exception e) 5YrBW:_OI
{ }*L(;r)q
e.printStackTrace (); E4hLtc^ +
} 5<w g8y
} 9*a=iL*Nw
h9eMcCU
//日志 5ls6t{Ci
public static void log(String sMsg) -{ZWo:,r~q
{ 0tU.(
System.err.println(sMsg); QV\eMuNy
} ` Jdb;
v,ju!I0.
F+u|HiYG
public static void log(int sMsg) ,{c?ymw?
{ F;]%V%F.X
System.err.println(sMsg); -a-(r'Qc(
} [Jv@J\
} #t+d iR
f%*/cpA)
8]LD]h)B"
/* Z4\=*ic@
**TestMethod.java Dtj&W<NXo
*/ Jkek-m
package NetFox; pxa(
4]E3cAJ
qT^I?g"!
public class TestMethod { Ng_!zrx04
)Eo)t>
K>{T_){
public TestMethod() 53[~bwD
{ ///xx/weblogic60b2_win.exe " W|%~h
try{ ~sXcnxLz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D"D<+ ;S#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JeE;V![
SiteFileFetch fileFetch = new SiteFileFetch(bean); dN$Tf
fileFetch.start(); E@b(1@
} )KAEt.
catch(Exception e){e.printStackTrace ();} rh^mJUh
r3PT1'P?L
&c,kQo+pA
} VzVc37Z>6
b1($R[
7"C$pm6
public static void main(String[] args) j}C}:\-fY
{ Ct>GYk$
new TestMethod(); UNBH
} HZ:6zH
} g?ULWeZg5
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