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)); oQ+61!5>
} L4f7s7rJ
for(int i=0;i<nEndPos.length-1;i++) o07IcIo
{ e,A)U5X
nEndPos = nStartPos[i+1]; YnV/M,U
} gdj^df+2F
nEndPos[nEndPos.length-1] = nFileLength; +?`b=6e(`
} @kD8^,(oH
} 8(X0 :
_|isa]u\z
wz -)1!
//启动子线程 TF+ l5fv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |kiJ}oy
for(int i=0;i<nStartPos.length;i++) EEf ]u7
{ R_Dc)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )"O{D`uX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6&2LWaWMo$
nStartPos,nEndPos,i); ;)!"Ty|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G5]1s
fileSplitterFetch.start(); 9-jO,l
} {,O`rW_eS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aw}+'(?8]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \Rk$t7ZH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", p*;Qz
nEndPos = " + nFileLength); "EftN5?/
// fileSplitterFetch[nPos.length-1].start(); qg,Nb
zXc}W*ymj
xQt 3[(Z
//等待子线程结束 a}.Y!O&
//int count = 0; :\V,k~asl
//是否结束while循环 ]@xL=%
boolean breakWhile = false; |Svk^mq
#A <1aQ
&A50'8B2A
while(!bStop) ,&a`d}g&G
{ "2HY5AE
write_nPos(); 4?]oV%aP)
Utility.sleep(500); T<jfAE
breakWhile = true; wFlV=!>,
DOL%'k?B
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for(int i=0;i<nStartPos.length;i++) !eD+GDgE]
{ L{ ^4DznI
if(!fileSplitterFetch.bDownOver) , &' Y
{ -a) T6:e
breakWhile = false; hH+bt!aH
break; _GbE^
} Z^tGu7x
} ged,>
if(breakWhile) gAE!aKy
break; CD?&<NV
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rH}fLu8,;Q
//count++; C%H9[%k
//if(count>4) oK-!(1A-
// siteStop(); IbdM9qo7
} A'eAu
t;Wotfc[#0
-gKpL\
System.err.println("文件下载结束！"); h-'wV${b
} 3;BvnD7
catch(Exception e){e.printStackTrace ();} VbxAd 2')
} jL4>A$
PvOC5b
P%GkcV
//获得文件长度 %RFYm
public long getFileSize() ch,|1}bi
{ R+. Nn
int nFileLength = -1; }V^e7d
try{ WV_`1hZX
URL url = new URL(siteInfoBean.getSSiteURL()); 52<~K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {^&k!H2
httpConnection.setRequestProperty("User-Agent","NetFox"); ;mJkqbVol
8gpBz'/,
Tt6{WDscZ
int responseCode=httpConnection.getResponseCode(); r>3^kL5UI
if(responseCode>=400) nu 7lh6o=
{ Lpm?#g uR
processErrorCode(responseCode); b:B[3|
return -2; //-2 represent access is error T]2U fi.
} U1^l+G^,~
k&DGJ5m$.
!`C?nY
String sHeader; eti9nPjG
/VtlG+dLl
w4OW4J#
for(int i=1;;i++) UA0tFeH
{ YmCbxYa7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4_< nQ9K
//Utility.log(in.readLine()); <P pYl
sHeader=httpConnection.getHeaderFieldKey(i); .;%q/hP
if(sHeader!=null) i^S2%qz
{ y*KC*/'"
if(sHeader.equals("Content-Length")) PdM*5g4
{ '(9YB9 i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]piM/v\
break; .v7`$(T
} 6~:+:;
} >x?2Fz.
else \L#QR
break; }*-u$=2
} 5vGioO
} Riq|w+Q
catch(IOException e){e.printStackTrace ();} ]|BojSL_
catch(Exception e){e.printStackTrace ();} E(/ sXji!
104!!m
: ~'Z(-a
Utility.log(nFileLength); S2}Z&X(
ZV#$Z
4@~a<P#
return nFileLength; afy/K'~
} SEU\}Ni{
K!7q!%Ju
O"QHb|j
//保存下载信息（文件指针位置） SauHFl8?
private void write_nPos() zkG>u,B}
{ 3*2I$e!Jt
try{ OgTSx
output = new DataOutputStream(new FileOutputStream(tmpFile)); Lv3XYZgW~
output.writeInt(nStartPos.length); :B+Rg cqi
for(int i=0;i<nStartPos.length;i++) To^# 0
{ /THNP 8.
// output.writeLong(nPos); 6ZTaQPtm
output.writeLong(fileSplitterFetch.nStartPos); Zr9d&|$
output.writeLong(fileSplitterFetch.nEndPos); @5GBuu^j
} @jKDj]\
output.close(); ,N0uR@GN
} >Pyc[_j
catch(IOException e){e.printStackTrace ();} @bY?$fj_u
catch(Exception e){e.printStackTrace ();} c G*(C
} 5Fr;
A~XOK;sB
>.LgsMRIKi
//读取保存的下载信息（文件指针位置） RCQAtBd
private void read_nPos() /+N|X
{ >.n;mk
try{ ennR@pg
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?Oqzd$-
int nCount = input.readInt(); |""=)-5N
nStartPos = new long[nCount]; ?'Oj=k"c7
nEndPos = new long[nCount]; QjqBO+
for(int i=0;i<nStartPos.length;i++) hXPocP
{ H)`@2~Y
nStartPos = input.readLong(); 6#O#T;f)
nEndPos = input.readLong(); /'mrDb_ip
} =9fEv,Jk
input.close(); SF"#\{cjj
} k=ts&9\
catch(IOException e){e.printStackTrace ();} ;Na^]32
catch(Exception e){e.printStackTrace ();} PaxK^*
} AzxL%,_
"0b?+ 3_{G
x'zihDOI
private void processErrorCode(int nErrorCode) 0s)cVYppe
{ OWZS3Y+
System.err.println("Error Code : " + nErrorCode); q;ZLaX\bFl
} RrKfTiK H
U>in2u9
k06xz#pL
//停止文件下载 Ma>:_0I5
public void siteStop() 6<<'bi
{ 5cgo)/3M@}
bStop = true; )tScc*=8
for(int i=0;i<nStartPos.length;i++) ))p$vU3
fileSplitterFetch.splitterStop(); -.^3;-[
):^ '/e
}'DC Q
} C`3V=BB
} LSSW.Oz2L
//负责部分文件的抓取 %V31B\]Nz7
**FileSplitterFetch.java WN$R[N
*/ 6zv;lx0<D&
package NetFox; amMjuyW
GKiq0*/M
{=s:P|ah
import java.io.*; "havi,m
import java.net.*; ob)Q,;8R
D DQs42[
sw[oQ!f
public class FileSplitterFetch extends Thread { {>wI8
m"<4\;GK
1B6C<cL:sU
String sURL; //File URL 8~.iuFp
long nStartPos; //File Snippet Start Position ';&0~[R[
long nEndPos; //File Snippet End Position Q! Kn|mnN
int nThreadID; //Thread's ID kkT3wP
boolean bDownOver = false; //Downing is over kJI3`gS+
boolean bStop = false; //Stop identical <b6s&"%=
FileAccessI fileAccessI = null; //File Access interface 7AI3|Ts]p
J`YnT
v#iFQVBq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Cy<T Vk8
{ L'13BRu`
this.sURL = sURL; &S<?07Z
this.nStartPos = nStart; x)j/
this.nEndPos = nEnd; I$+%~4
nThreadID = id; ax<g0=^R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LE8K)i
} ^eT@!N
K?9WY]Ot
"!xvpsy
public void run() "EN98^ Sl
{ UHr{
while(nStartPos < nEndPos && !bStop) {cmo^~[L$
{ ok%EqO
,>&?ty9o
tvTWZ`
try{ y*}AX%8`e~
URL url = new URL(sURL); O|?Z~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?E%U|(S)=L
httpConnection.setRequestProperty("User-Agent","NetFox"); &aY/eD
String sProperty = "bytes="+nStartPos+"-"; 5woIGO3X
httpConnection.setRequestProperty("RANGE",sProperty); KLG6QBkj
Utility.log(sProperty); 4sj9Z:
+Y^-e.UO
'uPxEu4 >4
InputStream input = httpConnection.getInputStream(); Sc%aJ1
//logResponseHead(httpConnection); l?})_1v,R
|.y>[+Qb*
L& I` #
byte[] b = new byte[1024]; 4\&H?:c.
int nRead; ?UxG/]",
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8rGl&
{ M_qP!+Y
nStartPos += fileAccessI.write(b,0,nRead); =>HIF#jU
//if(nThreadID == 1) #D/$6ah~m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); issT{&T
} -"2<h:#
v;K{|zUdB
RcY6V_Qx
Utility.log("Thread " + nThreadID + " is over!"); se~ *<5
bDownOver = true; :|?~B%-p[
//nPos = fileAccessI.write (b,0,nRead); 5OPS&:
} ?+bTPl;%'
catch(Exception e){e.printStackTrace ();} Tf9&,!>V
} JCM)N8~i
} Coga-: 2vu
-;sJ25(
aw%>YrJ
//打印回应的头信息 !}iLO0
public void logResponseHead(HttpURLConnection con) ;X+G6F'
{ }UyzMy,
for(int i=1;;i++) h{Oz*Bq
{ Sja"(sJ
String header=con.getHeaderFieldKey(i); U,oD44
if(header!=null) 4aj[5fhb-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t9-_a5>E\}
Utility.log(header+" : "+con.getHeaderField(header)); F(T=WR].o
else db{NKwpj'
break; j%6|:o3G(
} F6RyOUma
} M/n[&
~z\pI|DQ
L@C >-F|p
public void splitterStop() #cw! &
{ WpZy](,
bStop = true; 6b-
} ^?H\*N4
9`ri J4zl
wk-Mu\
} L~^e\^sP
)v*v
Ln"+nKr
/* K?z*3^^X;
**FileAccess.java u+%)JhIp
*//文件访问(定位，写) W)6U6
package NetFox; OU0xZ=G
import java.io.*; ,\|n=T,
]3gYuz|
[VfLv.8w
public class FileAccessI implements Serializable{ I T*fjUY&
N&R '$w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U92B+up-
RandomAccessFile oSavedFile; f9h:"Dnzin
long nPos; OGSEvfW
UMHuIA:%U
m _t(rn~f6
public FileAccessI() throws IOException |_Naun=+~
{ 9b{g+lMZo
this("",0); "2y7&#l
} iqU.a/~y
!nP8ysB
cHqvkN`
public FileAccessI(String sName,long nPos) throws IOException TzD:bKE&
{ o=a:L^nt,
oSavedFile = new RandomAccessFile(sName,"rw"); 7?kXgR[#d
this.nPos = nPos; #Pe\Z/
oSavedFile.seek(nPos); kphy7>Km
} !Szgph"ul
Li?{e+g
@Z3[c[D)9
public synchronized int write(byte[] b,int nStart,int nLen) &lXx0"-$
{ u;l6sdo
int n = -1; Apw-7*/
try{ 18[?dV
oSavedFile.write(b,nStart,nLen); 30gZ_8C>}
n = nLen; C%x(`S^/
} a=}">=]7
catch(IOException e) x|~D(zo
{ `Cb<KAaCH
e.printStackTrace (); uK"$=v6|
} ie$fMBIq
;X9MA=b
xX/Qoq (}i
return n; 1*c0\:BQ;z
} TkoCyD9
% @^VrhS
} (GQDJp
} B?/12+sR
D6pEQdX`
0qaG#&!
/* z-{"pI
**SiteInfoBean.java 2Wc;hJ.1
*/ 0X S' v,|
package NetFox; z9uEOX&2\
Eo25ir%
nvUkbmZG#
public class SiteInfoBean { =8VJ.{xy_e
o/i5e=9[y
5 \.TZMB
private String sSiteURL; //Site's URL N2S!.H!Wz
private String sFilePath; //Saved File's Path $fU/9jTa
private String sFileName; //Saved File's Name a*$1la'Uf
private int nSplitter; //Count of Splited Downloading File aaqjE
*$WiJ3'(m
?tal/uC
public SiteInfoBean() `rOe5Zp$
{//nSplitter的缺省值为5 ;M(ehX
//default value of nSplitter is 5 6|(7G64{
this("","","",5); &bOodkOb
} +kdU%Sm
Ff1M~MhG
*{4{<O<4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) sN[@mAoH
{ >P]I&S-.
sSiteURL= sURL; #L1yL<'
sFilePath = sPath; .q;RNCUt
sFileName = sName; XN0RT>@
this.nSplitter = nSpiltter; 802]M
=f{Z~`3
N;Gf,pE
} [/2@=Uh-
0,i+
-7A!2mRiz
public String getSSiteURL() A`r$fCt1Vi
{ (WU~e!}
return sSiteURL; Z!5m'yZO
} 5SPl#*W
*b7 ^s,?
oVj A$|
public void setSSiteURL(String value) s-YV_
{ _o=`-iy9
sSiteURL = value; \2LA%ZU
} ^!s}2GcS`
daokiU+l2
?_h#>
public String getSFilePath() f"}14V
{ d'eM(4R@
return sFilePath; ,:Y=,[n
} =S?-=jPtg
u BW
Ml_:Q]kl^
public void setSFilePath(String value) W} +6L|
{ oY#XWe8Om
sFilePath = value; IEKX'+t'
} Z#E#P<&d
TlZlE^EE<
6T'43h. :
public String getSFileName() 3By>t!~Q
{ "9Fv!*<-W
return sFileName; @0x.n\M_
} tGy%n[ \
cqU/Y_%l'
\=:g$_l
public void setSFileName(String value) ;U:o'9^9T
{ zYl+BM-j,6
sFileName = value; +Y%I0.?&5
} ^`C*";8Q
&wWGZ~T
/URj$|
public int getNSplitter() C @[9 LB
{ 9%hB
return nSplitter; -T="Ml&
} s_e#y{{C2
X]qp~:4G
kO\&mL& qD
public void setNSplitter(int nCount) kTe<1^,m
{ 'bqf?3W
nSplitter = nCount; <8}9s9Nk
} T)?@E/VaS
} WlJRKM2
<zWQ[^
Bf}0'MK8zQ
/* r-DD*'R
**Utility.java 4xC6#:8
*/ !P3tTL!*L
package NetFox; ViC76aJ
vf'jz`Z
UgBY ){<
public class Utility { ,}xC) >
5Szo5
HrcnyQ`Q0
public Utility() l~>rpG
{ gA8u E
*h8XbBZH
:zTj"P>"I
} HH7gT
\fGYJ37
//线程睡眠 9#ay(g
public static void sleep(int nSecond) < 2r#vmM
{ <L[)P{jn?p
try{ $TUC?e9"h
Thread.sleep(nSecond); mi3q1npb7[
} 8XXTN@&,
catch(Exception e) -^%"w
{ RB 0j!H:
e.printStackTrace (); = ~R3*GN
} >?\ !k c
} O4+w2'.,
Ki6BPi^
//日志 qdnNapWnc
public static void log(String sMsg) nFOG=>c}
{ l%V}'6T
System.err.println(sMsg); X>YOo~yS5
} wH5O>4LO
x~I1(l7r
VY26Cf"
public static void log(int sMsg) HCCp<2D"C
{ gnK!"!nL
System.err.println(sMsg); IBHG1<3
} Tl{r D(D
} )4O`%9=M&
MjosA R
:)S4MoG
/* x{w?X.Nt
**TestMethod.java %bETr"Xom
*/ )%W2XvG
package NetFox; 8U$UI
jWjK-q@Y
sm <kb@g
public class TestMethod { F}mwQ%M
t$Ji{t-
Z%d4V<fn
public TestMethod() ^E,UcK;
{ ///xx/weblogic60b2_win.exe aj~@r3E;
try{ {?_)m/\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aYX'&k `
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?-p aM5Q+
SiteFileFetch fileFetch = new SiteFileFetch(bean); "K=)J'/n
fileFetch.start(); bpCe&*\6K
} Z@Z`8M@Q,
catch(Exception e){e.printStackTrace ();} .=<pU k 3G
) FsSXnZL
$G.|5sEk
} U9%nku4
/R?uxhV
:H k4i%hGk
public static void main(String[] args) 2Nzcej
{ -igZU>0B_
new TestMethod(); B(NL3WJ
} p 8rAtz>=J
} +OP'/
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